12900561 has 4 divisors (see below), whose sum is σ = 17200752. Its totient is φ = 8600372.

The previous prime is 12900553. The next prime is 12900581. The reversal of 12900561 is 16500921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12900561 - 2³ = 12900553 is a prime.

It is a super-2 number, since 2×12900561² = 332848948229442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12900521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2150091 + ... + 2150096.

It is an arithmetic number, because the mean of its divisors is an integer number (4300188).

Almost surely, 2^12900561 is an apocalyptic number.

It is an amenable number.

12900561 is a deficient number, since it is larger than the sum of its proper divisors (4300191).

12900561 is an equidigital number, since it uses as much as digits as its factorization.

12900561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4300190.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 12900561 is about 3591.7350960225. The cubic root of 12900561 is about 234.5324096000.

The spelling of 12900561 in words is "twelve million, nine hundred thousand, five hundred sixty-one".