161666592720 has 40 divisors (see below), whose sum is σ = 501166438176. Its totient is φ = 43111091328.

The previous prime is 161666592701. The next prime is 161666592721. The reversal of 161666592720 is 27295666161.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×161666592720² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161666592721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 336805162 + ... + 336805641.

Almost surely, 2^161666592720 is an apocalyptic number.

161666592720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161666592720 is an abundant number, since it is smaller than the sum of its proper divisors (339499845456).

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

161666592720 is a wasteful number, since it uses less digits than its factorization.

161666592720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673610819 (or 673610813 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 51.

The spelling of 161666592720 in words is "one hundred sixty-one billion, six hundred sixty-six million, five hundred ninety-two thousand, seven hundred twenty".