21271336525 has 6 divisors (see below), whose sum is σ = 26376457322. Its totient is φ = 17017069200.

The previous prime is 21271336501. The next prime is 21271336561. The reversal of 21271336525 is 52563317212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 86825124 + 21184511401 = 9318^2 + 145549^2 .

It is not a de Polignac number, because 21271336525 - 2⁹ = 21271336013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 425426706 + ... + 425426755.

Almost surely, 2^21271336525 is an apocalyptic number.

21271336525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21271336525 is a deficient number, since it is larger than the sum of its proper divisors (5105120797).

21271336525 is an equidigital number, since it uses as much as digits as its factorization.

21271336525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850853471 (or 850853466 counting only the distinct ones).

The product of its digits is 75600, while the sum is 37.

The spelling of 21271336525 in words is "twenty-one billion, two hundred seventy-one million, three hundred thirty-six thousand, five hundred twenty-five".