21525430525 has 12 divisors (see below), whose sum is σ = 27611932500. Its totient is φ = 16626538880.

The previous prime is 21525430489. The next prime is 21525430529. The reversal of 21525430525 is 52503452512.

It can be written as a sum of positive squares in 6 ways, for example, as 2254160484 + 19271270041 = 47478^2 + 138821^2 .

It is not a de Polignac number, because 21525430525 - 2⁹ = 21525430013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525430529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14844400 + ... + 14845849.

It is an arithmetic number, because the mean of its divisors is an integer number (2300994375).

Almost surely, 2^21525430525 is an apocalyptic number.

21525430525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21525430525 is a deficient number, since it is larger than the sum of its proper divisors (6086501975).

21525430525 is a wasteful number, since it uses less digits than its factorization.

21525430525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29690288 (or 29690283 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 34.

The spelling of 21525430525 in words is "twenty-one billion, five hundred twenty-five million, four hundred thirty thousand, five hundred twenty-five".