21941015625 has 81 divisors (see below), whose sum is σ = 40123514613. Its totient is φ = 11553750000.

The previous prime is 21941015597. The next prime is 21941015633. The reversal of 21941015625 is 52651014912.

The square root of 21941015625 is 148125.

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

21941015625 is a `hidden beast` number, since 2 + 1 + 9 + 4 + 10 + 15 + 625 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 15599760201 + 6341255424 = 124899^2 + 79632^2 .

It is not a de Polignac number, because 21941015625 - 2⁹ = 21941015113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21941015625.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 277734336 + ... + 277734414.

Almost surely, 2^21941015625 is an apocalyptic number.

21941015625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21941015625 is the 148125-th square number.

21941015625 is the 74063-rd centered octagonal number.

It is an amenable number.

21941015625 is a deficient number, since it is larger than the sum of its proper divisors (18182498988).

21941015625 is an frugal number, since it uses more digits than its factorization.

21941015625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

Multiplying 21941015625 by its sum of digits (36), we get a square (789876562500 = 888750²).

The spelling of 21941015625 in words is "twenty-one billion, nine hundred forty-one million, fifteen thousand, six hundred twenty-five".