25213531161 has 32 divisors (see below), whose sum is σ = 42802824960. Its totient is φ = 12840839424.

The previous prime is 25213531157. The next prime is 25213531169. The reversal of 25213531161 is 16113531252.

It is not a de Polignac number, because 25213531161 - 2² = 25213531157 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25213531169) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1584450 + ... + 1600283.

It is an arithmetic number, because the mean of its divisors is an integer number (1337588280).

Almost surely, 2^25213531161 is an apocalyptic number.

25213531161 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25213531161 is a deficient number, since it is larger than the sum of its proper divisors (17589293799).

25213531161 is a wasteful number, since it uses less digits than its factorization.

25213531161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3184785.

The product of its digits is 5400, while the sum is 30.

Subtracting from 25213531161 its reverse (16113531252), we obtain a palindrome (9099999909).

The spelling of 25213531161 in words is "twenty-five billion, two hundred thirteen million, five hundred thirty-one thousand, one hundred sixty-one".