21115234025 has 24 divisors (see below), whose sum is σ = 26472305664. Its totient is φ = 16705728000.

The previous prime is 21115233977. The next prime is 21115234067. The reversal of 21115234025 is 52043251112.

It is not a de Polignac number, because 21115234025 - 2⁶ = 21115233961 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21115233985 and 21115234003.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4728944 + ... + 4733406.

It is an arithmetic number, because the mean of its divisors is an integer number (1103012736).

Almost surely, 2^21115234025 is an apocalyptic number.

21115234025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21115234025 is a deficient number, since it is larger than the sum of its proper divisors (5357071639).

21115234025 is a wasteful number, since it uses less digits than its factorization.

21115234025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6521 (or 6516 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21115234025 its reverse (52043251112), we get a palindrome (73158485137).

The spelling of 21115234025 in words is "twenty-one billion, one hundred fifteen million, two hundred thirty-four thousand, twenty-five".