25156861031 has 4 divisors (see below), whose sum is σ = 25836776232. Its totient is φ = 24476945832.

The previous prime is 25156861021. The next prime is 25156861033. The reversal of 25156861031 is 13016865152.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25156861031 is a prime.

It is a super-2 number, since 2×25156861031² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25156861033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 339957545 + ... + 339957618.

It is an arithmetic number, because the mean of its divisors is an integer number (6459194058).

Almost surely, 2^25156861031 is an apocalyptic number.

25156861031 is a deficient number, since it is larger than the sum of its proper divisors (679915201).

25156861031 is an equidigital number, since it uses as much as digits as its factorization.

25156861031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 679915200.

The product of its (nonzero) digits is 43200, while the sum is 38.

The spelling of 25156861031 in words is "twenty-five billion, one hundred fifty-six million, eight hundred sixty-one thousand, thirty-one".