1556611661000 has 64 divisors (see below), whose sum is σ = 3973605068160. Its totient is φ = 566040600000.

The previous prime is 1556611660999. The next prime is 1556611661029. The reversal of 1556611661000 is 1661166551.

It is a super-2 number, since 2×1556611661000² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70744076 + ... + 70766075.

It is an arithmetic number, because the mean of its divisors is an integer number (62087579190).

Almost surely, 2^{1556611661000} is an apocalyptic number.

1556611661000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1556611661000 is an abundant number, since it is smaller than the sum of its proper divisors (2416993407160).

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

1556611661000 is a wasteful number, since it uses less digits than its factorization.

1556611661000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141510183 (or 141510169 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 38.

The spelling of 1556611661000 in words is "one trillion, five hundred fifty-six billion, six hundred eleven million, six hundred sixty-one thousand".