161511660 has 72 divisors (see below), whose sum is σ = 503180496. Its totient is φ = 41904000.

The previous prime is 161511653. The next prime is 161511661. The reversal of 161511660 is 66115161.

It is not an unprimeable number, because it can be changed into a prime (161511661) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 5466 + ... + 18785.

It is an arithmetic number, because the mean of its divisors is an integer number (6988618).

Almost surely, 2^161511660 is an apocalyptic number.

161511660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161511660 is an abundant number, since it is smaller than the sum of its proper divisors (341668836).

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

161511660 is a wasteful number, since it uses less digits than its factorization.

161511660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24303 (or 24298 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 161511660 is about 12708.7237754229. The cubic root of 161511660 is about 544.5878656202.

The spelling of 161511660 in words is "one hundred sixty-one million, five hundred eleven thousand, six hundred sixty".