1256618020 has 48 divisors (see below), whose sum is σ = 3089455488. Its totient is φ = 420330240.

The previous prime is 1256618017. The next prime is 1256618023. The reversal of 1256618020 is 208166521.

It is an interprime number because it is at equal distance from previous prime (1256618017) and next prime (1256618023).

It is not an unprimeable number, because it can be changed into a prime (1256618023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103722 + ... + 115201.

It is an arithmetic number, because the mean of its divisors is an integer number (64363656).

Almost surely, 2^1256618020 is an apocalyptic number.

1256618020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1256618020 is an abundant number, since it is smaller than the sum of its proper divisors (1832837468).

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

1256618020 is a wasteful number, since it uses less digits than its factorization.

1256618020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218980 (or 218978 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 1256618020 is about 35448.8084425979. The cubic root of 1256618020 is about 1079.1150787310.

The spelling of 1256618020 in words is "one billion, two hundred fifty-six million, six hundred eighteen thousand, twenty".