25420213531 has 4 divisors (see below), whose sum is σ = 25501950864. Its totient is φ = 25338476200.

The previous prime is 25420213477. The next prime is 25420213537. The reversal of 25420213531 is 13531202452.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 25420213531 - 2¹⁵ = 25420180763 is a prime.

It is a super-2 number, since 2×25420213531² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25420213531.

It is not an unprimeable number, because it can be changed into a prime (25420213537) 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, 40868200 + ... + 40868821.

It is an arithmetic number, because the mean of its divisors is an integer number (6375487716).

Almost surely, 2^25420213531 is an apocalyptic number.

25420213531 is a deficient number, since it is larger than the sum of its proper divisors (81737333).

25420213531 is an equidigital number, since it uses as much as digits as its factorization.

25420213531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81737332.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 25420213531 its reverse (13531202452), we get a palindrome (38951415983).

The spelling of 25420213531 in words is "twenty-five billion, four hundred twenty million, two hundred thirteen thousand, five hundred thirty-one".