21121423425 has 18 divisors (see below), whose sum is σ = 37830816582. Its totient is φ = 11264759040.

The previous prime is 21121423327. The next prime is 21121423447. The reversal of 21121423425 is 52432412112.

21121423425 is a `hidden beast` number, since 2 + 1 + 1 + 214 + 23 + 425 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 1136229264 + 19985194161 = 33708^2 + 141369^2 .

It is not a de Polignac number, because 21121423425 - 2²⁵ = 21087868993 is a prime.

It is a super-2 number, since 2×21121423425² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 46936272 + ... + 46936721.

Almost surely, 2^21121423425 is an apocalyptic number.

21121423425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21121423425 is a deficient number, since it is larger than the sum of its proper divisors (16709393157).

21121423425 is a wasteful number, since it uses less digits than its factorization.

21121423425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93873009 (or 93873001 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

Adding to 21121423425 its reverse (52432412112), we get a palindrome (73553835537).

The spelling of 21121423425 in words is "twenty-one billion, one hundred twenty-one million, four hundred twenty-three thousand, four hundred twenty-five".