2101580649 has 81 divisors (see below), whose sum is σ = 3691800567. Its totient is φ = 1148642208.

The previous prime is 2101580641. The next prime is 2101580653. The reversal of 2101580649 is 9460851012.

The square root of 2101580649 is 45843.

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

2101580649 is a `hidden beast` number, since 2 + 1 + 0 + 1 + 5 + 8 + 0 + 649 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1880523225 + 221057424 = 43365^2 + 14868^2 .

It is not a de Polignac number, because 2101580649 - 2³ = 2101580641 is a prime.

It is a super-2 number, since 2×2101580649² = 8833282448502522402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2101580641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 35619982 + ... + 35620040.

Almost surely, 2^2101580649 is an apocalyptic number.

2101580649 is the 45843-rd square number.

2101580649 is the 22922-nd centered octagonal number.

It is an amenable number.

2101580649 is a deficient number, since it is larger than the sum of its proper divisors (1590219918).

2101580649 is an equidigital number, since it uses as much as digits as its factorization.

2101580649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The cubic root of 2101580649 is about 1280.9003774537.

Multiplying 2101580649 by its sum of digits (36), we get a square (75656903364 = 275058²).

The spelling of 2101580649 in words is "two billion, one hundred one million, five hundred eighty thousand, six hundred forty-nine".