161639994 has 8 divisors (see below), whose sum is σ = 323280000. Its totient is φ = 53879996.

The previous prime is 161639981. The next prime is 161640001. The reversal of 161639994 is 499936161.

161639994 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

161639994 is an admirable number.

It is a super-2 number, since 2×161639994² = 52254975320640072, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13469994 + ... + 13470005.

It is an arithmetic number, because the mean of its divisors is an integer number (40410000).

Almost surely, 2^161639994 is an apocalyptic number.

161639994 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

161639994 is a wasteful number, since it uses less digits than its factorization.

161639994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26940004.

The product of its digits is 314928, while the sum is 48.

The square root of 161639994 is about 12713.7718242857. The cubic root of 161639994 is about 544.7320670491.

The spelling of 161639994 in words is "one hundred sixty-one million, six hundred thirty-nine thousand, nine hundred ninety-four".