25056031521 has 4 divisors (see below), whose sum is σ = 33408042032. Its totient is φ = 16704021012.

The previous prime is 25056031499. The next prime is 25056031529. The reversal of 25056031521 is 12513065052.

It is a happy number.

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 not a de Polignac number, because 25056031521 - 2¹¹ = 25056029473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25056031529) 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, 4176005251 + ... + 4176005256.

It is an arithmetic number, because the mean of its divisors is an integer number (8352010508).

Almost surely, 2^25056031521 is an apocalyptic number.

It is an amenable number.

25056031521 is a deficient number, since it is larger than the sum of its proper divisors (8352010511).

25056031521 is an equidigital number, since it uses as much as digits as its factorization.

25056031521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8352010510.

The product of its (nonzero) digits is 9000, while the sum is 30.

Adding to 25056031521 its reverse (12513065052), we get a palindrome (37569096573).

The spelling of 25056031521 in words is "twenty-five billion, fifty-six million, thirty-one thousand, five hundred twenty-one".