161351640 has 48 divisors (see below), whose sum is σ = 524394000. Its totient is φ = 43027008.

The previous prime is 161351633. The next prime is 161351651. The reversal of 161351640 is 46153161.

161351640 is a `hidden beast` number, since 1 + 6 + 13 + 5 + 1 + 640 = 666.

161351640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 223740 + ... + 224459.

It is an arithmetic number, because the mean of its divisors is an integer number (10924875).

Almost surely, 2^161351640 is an apocalyptic number.

161351640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161351640 is an abundant number, since it is smaller than the sum of its proper divisors (363042360).

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

161351640 is a wasteful number, since it uses less digits than its factorization.

161351640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448216 (or 448209 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 161351640 is about 12702.4265398388. The cubic root of 161351640 is about 544.4079534369.

The spelling of 161351640 in words is "one hundred sixty-one million, three hundred fifty-one thousand, six hundred forty".