1280208400 has 45 divisors (see below), whose sum is σ = 3077420871. Its totient is φ = 511797120.

The previous prime is 1280208389. The next prime is 1280208437. The reversal of 1280208400 is 48020821.

The square root of 1280208400 is 35780.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 200165904 + 1080042496 = 14148^2 + 32864^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 714706 + ... + 716494.

Almost surely, 2^1280208400 is an apocalyptic number.

1280208400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1280208400 is the 35780-th square number.

It is an amenable number.

1280208400 is an abundant number, since it is smaller than the sum of its proper divisors (1797212471).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1280208400 is an frugal number, since it uses more digits than its factorization.

1280208400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3596 (or 1796 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The cubic root of 1280208400 is about 1085.8259689227.

Multiplying 1280208400 by its sum of digits (25), we get a square (32005210000 = 178900²).

1280208400 divided by its sum of digits (25) gives a square (51208336 = 7156²).

Multiplying 1280208400 by its product of nonzero digits (1024), we get a square (1310933401600 = 1144960²).

The spelling of 1280208400 in words is "one billion, two hundred eighty million, two hundred eight thousand, four hundred".