161556646 has 16 divisors (see below), whose sum is σ = 259041888. Its totient is φ = 75380800.

The previous prime is 161556617. The next prime is 161556653. The reversal of 161556646 is 646655161.

It is a super-2 number, since 2×161556646² = 52201099733538632, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161556599 and 161556608.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40945 + ... + 44716.

It is an arithmetic number, because the mean of its divisors is an integer number (16190118).

Almost surely, 2^161556646 is an apocalyptic number.

161556646 is a deficient number, since it is larger than the sum of its proper divisors (97485242).

161556646 is a wasteful number, since it uses less digits than its factorization.

161556646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85727.

The product of its digits is 129600, while the sum is 40.

The square root of 161556646 is about 12710.4935388049. The cubic root of 161556646 is about 544.6384224562.

It can be divided in two parts, 16155 and 6646, that added together give a square (22801 = 151²).

The spelling of 161556646 in words is "one hundred sixty-one million, five hundred fifty-six thousand, six hundred forty-six".