21572713025 has 6 divisors (see below), whose sum is σ = 26750164182. Its totient is φ = 17258170400.

The previous prime is 21572713021. The next prime is 21572713049. The reversal of 21572713025 is 52031727512.

It can be written as a sum of positive squares in 3 ways, for example, as 6753059329 + 14819653696 = 82177^2 + 121736^2 .

It is not a de Polignac number, because 21572713025 - 2² = 21572713021 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21572713021) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 431454236 + ... + 431454285.

It is an arithmetic number, because the mean of its divisors is an integer number (4458360697).

Almost surely, 2^21572713025 is an apocalyptic number.

21572713025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21572713025 is a deficient number, since it is larger than the sum of its proper divisors (5177451157).

21572713025 is an equidigital number, since it uses as much as digits as its factorization.

21572713025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862908531 (or 862908526 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 35.

The spelling of 21572713025 in words is "twenty-one billion, five hundred seventy-two million, seven hundred thirteen thousand, twenty-five".