161399292621 has 64 divisors (see below), whose sum is σ = 256516416000. Its totient is φ = 88316928000.

The previous prime is 161399292611. The next prime is 161399292631. The reversal of 161399292621 is 126292993161.

It is an interprime number because it is at equal distance from previous prime (161399292611) and next prime (161399292631).

It is not a de Polignac number, because 161399292621 - 2²¹ = 161397195469 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161399292611) 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 63 ways as a sum of consecutive naturals, for example, 108979201 + ... + 108980681.

It is an arithmetic number, because the mean of its divisors is an integer number (4008069000).

Almost surely, 2^161399292621 is an apocalyptic number.

It is an amenable number.

161399292621 is a deficient number, since it is larger than the sum of its proper divisors (95117123379).

161399292621 is a wasteful number, since it uses less digits than its factorization.

161399292621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2870.

The product of its digits is 629856, while the sum is 51.

The spelling of 161399292621 in words is "one hundred sixty-one billion, three hundred ninety-nine million, two hundred ninety-two thousand, six hundred twenty-one".