161620884441 has 45 divisors (see below), whose sum is σ = 254917922853. Its totient is φ = 102032929800.

The previous prime is 161620884413. The next prime is 161620884461. The reversal of 161620884441 is 144488026161.

The square root of 161620884441 is 402021.

It is a perfect power (a square), and thus also a powerful number.

161620884441 is a `hidden beast` number, since 1 + 616 + 20 + 8 + 8 + 4 + 4 + 4 + 1 = 666.

It is not a de Polignac number, because 161620884441 - 2²³ = 161612495833 is a prime.

It is a super-2 number, since 2×161620884441² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161620884401) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 68744416 + ... + 68746766.

Almost surely, 2^161620884441 is an apocalyptic number.

161620884441 is the 402021-st square number.

161620884441 is the 201011-st centered octagonal number.

It is an amenable number.

161620884441 is a deficient number, since it is larger than the sum of its proper divisors (93297038412).

161620884441 is an frugal number, since it uses more digits than its factorization.

161620884441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4752 (or 2373 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The spelling of 161620884441 in words is "one hundred sixty-one billion, six hundred twenty million, eight hundred eighty-four thousand, four hundred forty-one".