161657445 has 16 divisors (see below), whose sum is σ = 259050240. Its totient is φ = 86084544.

The previous prime is 161657413. The next prime is 161657549. The reversal of 161657445 is 544756161.

It is not a de Polignac number, because 161657445 - 2⁵ = 161657413 is a prime.

It is a super-2 number, since 2×161657445² = 52266259047856050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2196 + ... + 18114.

It is an arithmetic number, because the mean of its divisors is an integer number (16190640).

Almost surely, 2^161657445 is an apocalyptic number.

161657445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161657445 is a deficient number, since it is larger than the sum of its proper divisors (97392795).

161657445 is a wasteful number, since it uses less digits than its factorization.

161657445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16604.

The product of its digits is 100800, while the sum is 39.

The square root of 161657445 is about 12714.4581087831. The cubic root of 161657445 is about 544.7516698239.

The spelling of 161657445 in words is "one hundred sixty-one million, six hundred fifty-seven thousand, four hundred forty-five".