25401222121 has 16 divisors (see below), whose sum is σ = 28199927808. Its totient is φ = 22687635600.

The previous prime is 25401222109. The next prime is 25401222157. The reversal of 25401222121 is 12122210452.

It is not a de Polignac number, because 25401222121 - 2⁵ = 25401222089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25401222092 and 25401222101.

It is not an unprimeable number, because it can be changed into a prime (25401222101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55626 + ... + 232156.

It is an arithmetic number, because the mean of its divisors is an integer number (1762495488).

Almost surely, 2^25401222121 is an apocalyptic number.

It is an amenable number.

25401222121 is a deficient number, since it is larger than the sum of its proper divisors (2798705687).

25401222121 is a wasteful number, since it uses less digits than its factorization.

25401222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176772.

The product of its (nonzero) digits is 640, while the sum is 22.

Adding to 25401222121 its reverse (12122210452), we get a palindrome (37523432573).

The spelling of 25401222121 in words is "twenty-five billion, four hundred one million, two hundred twenty-two thousand, one hundred twenty-one".