21574028161 has 9 divisors (see below), whose sum is σ = 25097514561. Its totient is φ = 18491142852.

The previous prime is 21574028141. The next prime is 21574028167. The reversal of 21574028161 is 16182047512.

The square root of 21574028161 is 146881.

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

It is not a de Polignac number, because 21574028161 - 2⁷ = 21574028033 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21574028161.

It is not an unprimeable number, because it can be changed into a prime (21574028167) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1017676 + ... + 1038658.

It is an arithmetic number, because the mean of its divisors is an integer number (2788612729).

Almost surely, 2^21574028161 is an apocalyptic number.

21574028161 is the 146881-st square number.

21574028161 is the 73441-st centered octagonal number.

It is an amenable number.

21574028161 is a deficient number, since it is larger than the sum of its proper divisors (3523486400).

21574028161 is an frugal number, since it uses more digits than its factorization.

21574028161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41980 (or 20990 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The spelling of 21574028161 in words is "twenty-one billion, five hundred seventy-four million, twenty-eight thousand, one hundred sixty-one".