1256889136 has 20 divisors (see below), whose sum is σ = 2439520200. Its totient is φ = 627335552.

The previous prime is 1256889103. The next prime is 1256889143. The reversal of 1256889136 is 6319886521.

It is a self number, because there is not a number n which added to its sum of digits gives 1256889136.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59926 + ... + 78133.

It is an arithmetic number, because the mean of its divisors is an integer number (121976010).

Almost surely, 2^1256889136 is an apocalyptic number.

1256889136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1256889136 is a deficient number, since it is larger than the sum of its proper divisors (1182631064).

1256889136 is a wasteful number, since it uses less digits than its factorization.

1256889136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138636 (or 138630 counting only the distinct ones).

The product of its digits is 622080, while the sum is 49.

The square root of 1256889136 is about 35452.6322859107. The cubic root of 1256889136 is about 1079.1926796994.

The spelling of 1256889136 in words is "one billion, two hundred fifty-six million, eight hundred eighty-nine thousand, one hundred thirty-six".