1271321856 has 162 divisors, whose sum is σ = 4264367562. Its totient is φ = 363202560.

The previous prime is 1271321773. The next prime is 1271321879. The reversal of 1271321856 is 6581231721.

It can be written as a sum of positive squares in only one way, i.e., 1268499456 + 2822400 = 35616^2 + 1680^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1271321856.

It is a congruent 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 17 ways as a sum of consecutive naturals, for example, 107266 + ... + 118526.

Almost surely, 2^1271321856 is an apocalyptic number.

1271321856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1271321856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2132183781).

1271321856 is an abundant number, since it is smaller than the sum of its proper divisors (2993045706).

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

1271321856 is a wasteful number, since it uses less digits than its factorization.

1271321856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11297 (or 11273 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 1271321856 is about 35655.6006259886. The cubic root of 1271321856 is about 1083.3077191787.

The spelling of 1271321856 in words is "one billion, two hundred seventy-one million, three hundred twenty-one thousand, eight hundred fifty-six".