161556151666 has 32 divisors (see below), whose sum is σ = 299819132928. Its totient is φ = 63577690560.

The previous prime is 161556151643. The next prime is 161556151727. The reversal of 161556151666 is 666151655161.

It is a super-2 number, since 2×161556151666² (a number of 23 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, 2288985 + ... + 2358508.

It is an arithmetic number, because the mean of its divisors is an integer number (9369347904).

Almost surely, 2^161556151666 is an apocalyptic number.

161556151666 is a deficient number, since it is larger than the sum of its proper divisors (138262981262).

161556151666 is a wasteful number, since it uses less digits than its factorization.

161556151666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4647706.

The product of its digits is 972000, while the sum is 49.

The spelling of 161556151666 in words is "one hundred sixty-one billion, five hundred fifty-six million, one hundred fifty-one thousand, six hundred sixty-six".