21310724525 has 6 divisors (see below), whose sum is σ = 26425298442. Its totient is φ = 17048579600.

The previous prime is 21310724503. The next prime is 21310724531. The reversal of 21310724525 is 52542701312.

It can be written as a sum of positive squares in 3 ways, for example, as 6813842116 + 14496882409 = 82546^2 + 120403^2 .

It is not a de Polignac number, because 21310724525 - 2¹⁰ = 21310723501 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21310724491 and 21310724500.

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, 426214466 + ... + 426214515.

It is an arithmetic number, because the mean of its divisors is an integer number (4404216407).

Almost surely, 2^21310724525 is an apocalyptic number.

21310724525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21310724525 is a deficient number, since it is larger than the sum of its proper divisors (5114573917).

21310724525 is an equidigital number, since it uses as much as digits as its factorization.

21310724525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852428991 (or 852428986 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 32.

The spelling of 21310724525 in words is "twenty-one billion, three hundred ten million, seven hundred twenty-four thousand, five hundred twenty-five".