161645190 has 32 divisors (see below), whose sum is σ = 443370240. Its totient is φ = 36947424.

The previous prime is 161645189. The next prime is 161645227. The reversal of 161645190 is 91546161.

It is a super-2 number, since 2×161645190² = 52258334900272200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

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, 384660 + ... + 385079.

It is an arithmetic number, because the mean of its divisors is an integer number (13855320).

Almost surely, 2^161645190 is an apocalyptic number.

161645190 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161645190 is an abundant number, since it is smaller than the sum of its proper divisors (281725050).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161645190 is a wasteful number, since it uses less digits than its factorization.

161645190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769756.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 161645190 is about 12713.9761679814. The cubic root of 161645190 is about 544.7379038832.

The spelling of 161645190 in words is "one hundred sixty-one million, six hundred forty-five thousand, one hundred ninety".