161371621 has 4 divisors (see below), whose sum is σ = 161406432. Its totient is φ = 161336812.

The previous prime is 161371601. The next prime is 161371627. The reversal of 161371621 is 126173161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161371621 - 2⁵ = 161371589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161371621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161371627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9145 + ... + 20158.

It is an arithmetic number, because the mean of its divisors is an integer number (40351608).

Almost surely, 2^161371621 is an apocalyptic number.

It is an amenable number.

161371621 is a deficient number, since it is larger than the sum of its proper divisors (34811).

161371621 is an equidigital number, since it uses as much as digits as its factorization.

161371621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34810.

The product of its digits is 1512, while the sum is 28.

The square root of 161371621 is about 12703.2130187603. The cubic root of 161371621 is about 544.4304247844.

The spelling of 161371621 in words is "one hundred sixty-one million, three hundred seventy-one thousand, six hundred twenty-one".