1556666556 has 24 divisors (see below), whose sum is σ = 3639372240. Its totient is φ = 517867392.

The previous prime is 1556666549. The next prime is 1556666567. The reversal of 1556666556 is 6556666551.

It is a super-2 number, since 2×1556666556² = 4846421533137802272, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1556666499 and 1556666508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121321 + ... + 133536.

It is an arithmetic number, because the mean of its divisors is an integer number (151640510).

Almost surely, 2^1556666556 is an apocalyptic number.

It is an amenable number.

1556666556 is an abundant number, since it is smaller than the sum of its proper divisors (2082705684).

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

1556666556 is a wasteful number, since it uses less digits than its factorization.

1556666556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255373 (or 255371 counting only the distinct ones).

The product of its digits is 4860000, while the sum is 51.

The square root of 1556666556 is about 39454.6138746788. The cubic root of 1556666556 is about 1158.9513303034.

The spelling of 1556666556 in words is "one billion, five hundred fifty-six million, six hundred sixty-six thousand, five hundred fifty-six".