161620451 has 16 divisors (see below), whose sum is σ = 171763200. Its totient is φ = 151824288.

The previous prime is 161620447. The next prime is 161620463. The reversal of 161620451 is 154026161.

It is not a de Polignac number, because 161620451 - 2² = 161620447 is a prime.

It is a super-2 number, since 2×161620451² = 52242340362886802, which contains 22 as substring.

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 161620451.

It is not an unprimeable number, because it can be changed into a prime (161620421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 385520 + ... + 385938.

It is an arithmetic number, because the mean of its divisors is an integer number (10735200).

Almost surely, 2^161620451 is an apocalyptic number.

161620451 is a deficient number, since it is larger than the sum of its proper divisors (10142749).

161620451 is a wasteful number, since it uses less digits than its factorization.

161620451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 161620451 is about 12713.0032250448. The cubic root of 161620451 is about 544.7101126478.

The spelling of 161620451 in words is "one hundred sixty-one million, six hundred twenty thousand, four hundred fifty-one".