161661057 has 16 divisors (see below), whose sum is σ = 218393280. Its totient is φ = 106359552.

The previous prime is 161660999. The next prime is 161661083. The reversal of 161661057 is 750166161.

It is not a de Polignac number, because 161661057 - 2⁷ = 161660929 is a prime.

It is a super-2 number, since 2×161661057² = 52268594700714498, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161661257) 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, 99669 + ... + 101277.

It is an arithmetic number, because the mean of its divisors is an integer number (13649580).

Almost surely, 2^161661057 is an apocalyptic number.

It is an amenable number.

161661057 is a deficient number, since it is larger than the sum of its proper divisors (56732223).

161661057 is a wasteful number, since it uses less digits than its factorization.

161661057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2032.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 161661057 is about 12714.6001510075. The cubic root of 161661057 is about 544.7557270211.

The spelling of 161661057 in words is "one hundred sixty-one million, six hundred sixty-one thousand, fifty-seven".