25479397821 has 8 divisors (see below), whose sum is σ = 33974203744. Its totient is φ = 16985428560.

The previous prime is 25479397813. The next prime is 25479397843. The reversal of 25479397821 is 12879397452.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 25479397821 - 2³ = 25479397813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25479397121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134275 + ... + 262656.

It is an arithmetic number, because the mean of its divisors is an integer number (4246775468).

Almost surely, 2^25479397821 is an apocalyptic number.

It is an amenable number.

25479397821 is a deficient number, since it is larger than the sum of its proper divisors (8494805923).

25479397821 is a wasteful number, since it uses less digits than its factorization.

25479397821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418331.

The product of its digits is 7620480, while the sum is 57.

The spelling of 25479397821 in words is "twenty-five billion, four hundred seventy-nine million, three hundred ninety-seven thousand, eight hundred twenty-one".