1256563900 has 36 divisors (see below), whose sum is σ = 2793258720. Its totient is φ = 490364800.

The previous prime is 1256563897. The next prime is 1256563907. The reversal of 1256563900 is 93656521.

It is a self number, because there is not a number n which added to its sum of digits gives 1256563900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256563907) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 149140 + ... + 157339.

It is an arithmetic number, because the mean of its divisors is an integer number (77590520).

Almost surely, 2^1256563900 is an apocalyptic number.

1256563900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1256563900 is an abundant number, since it is smaller than the sum of its proper divisors (1536694820).

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

1256563900 is a wasteful number, since it uses less digits than its factorization.

1256563900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306534 (or 306527 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 1256563900 is about 35448.0450800887. The cubic root of 1256563900 is about 1079.0995867396.

The spelling of 1256563900 in words is "one billion, two hundred fifty-six million, five hundred sixty-three thousand, nine hundred".