21123131221425 has 12 divisors (see below), whose sum is σ = 34923576952880. Its totient is φ = 11265669984720.

The previous prime is 21123131221343. The next prime is 21123131221427. The reversal of 21123131221425 is 52412213132112.

It is not a de Polignac number, because 21123131221425 - 2⁹ = 21123131220913 is a prime.

It is a super-2 number, since 2×21123131221425² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21123131221392 and 21123131221401.

It is not an unprimeable number, because it can be changed into a prime (21123131221427) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140820874735 + ... + 140820874884.

Almost surely, 2^{21123131221425} is an apocalyptic number.

21123131221425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21123131221425 is a deficient number, since it is larger than the sum of its proper divisors (13800445731455).

21123131221425 is a wasteful number, since it uses less digits than its factorization.

21123131221425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281641749632 (or 281641749627 counting only the distinct ones).

The product of its digits is 5760, while the sum is 30.

Adding to 21123131221425 its reverse (52412213132112), we get a palindrome (73535344353537).

The spelling of 21123131221425 in words is "twenty-one trillion, one hundred twenty-three billion, one hundred thirty-one million, two hundred twenty-one thousand, four hundred twenty-five".