21525412513 has 4 divisors (see below), whose sum is σ = 23482268208. Its totient is φ = 19568556820.

The previous prime is 21525412481. The next prime is 21525412561. The reversal of 21525412513 is 31521452512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21525412513 - 2⁵ = 21525412481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21525482513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 978427831 + ... + 978427852.

It is an arithmetic number, because the mean of its divisors is an integer number (5870567052).

Almost surely, 2^21525412513 is an apocalyptic number.

It is an amenable number.

21525412513 is a deficient number, since it is larger than the sum of its proper divisors (1956855695).

21525412513 is a wasteful number, since it uses less digits than its factorization.

21525412513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1956855694.

The product of its digits is 12000, while the sum is 31.

The spelling of 21525412513 in words is "twenty-one billion, five hundred twenty-five million, four hundred twelve thousand, five hundred thirteen".