161606557 has 12 divisors (see below), whose sum is σ = 188225856. Its totient is φ = 138347160.

The previous prime is 161606527. The next prime is 161606581. The reversal of 161606557 is 755606161.

It is a de Polignac number, because none of the positive numbers 2^k-161606557 is a prime.

It is a super-2 number, since 2×161606557² = 52233358530788498, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161606527) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51948 + ... + 54970.

It is an arithmetic number, because the mean of its divisors is an integer number (15685488).

Almost surely, 2^161606557 is an apocalyptic number.

It is an amenable number.

161606557 is a deficient number, since it is larger than the sum of its proper divisors (26619299).

161606557 is a wasteful number, since it uses less digits than its factorization.

161606557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4128 (or 4121 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 161606557 is about 12712.4567649216. The cubic root of 161606557 is about 544.6945031975.

The spelling of 161606557 in words is "one hundred sixty-one million, six hundred six thousand, five hundred fifty-seven".