25495876981 has 4 divisors (see below), whose sum is σ = 25498461964. Its totient is φ = 25493292000.

The previous prime is 25495876969. The next prime is 25495877023. The reversal of 25495876981 is 18967859452.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17591777956 + 7904099025 = 132634^2 + 88905^2 .

It is a cyclic number.

It is not a de Polignac number, because 25495876981 - 2⁷ = 25495876853 is a prime.

It is a super-2 number, since 2×25495876981² (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 (25495876951) 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, 1277640 + ... + 1297441.

It is an arithmetic number, because the mean of its divisors is an integer number (6374615491).

Almost surely, 2^25495876981 is an apocalyptic number.

It is an amenable number.

25495876981 is a deficient number, since it is larger than the sum of its proper divisors (2584983).

25495876981 is an equidigital number, since it uses as much as digits as its factorization.

25495876981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2584982.

The product of its digits is 43545600, while the sum is 64.

The spelling of 25495876981 in words is "twenty-five billion, four hundred ninety-five million, eight hundred seventy-six thousand, nine hundred eighty-one".