21115325 has 36 divisors (see below), whose sum is σ = 33247872. Its totient is φ = 13154400.

The previous prime is 21115307. The next prime is 21115331. The reversal of 21115325 is 52351112.

21115325 = 907² + 908² + ... + 931².

It is a happy number.

It is not a de Polignac number, because 21115325 - 2⁶ = 21115261 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21115297 and 21115306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 12692 + ... + 14258.

It is an arithmetic number, because the mean of its divisors is an integer number (923552).

Almost surely, 2^21115325 is an apocalyptic number.

21115325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21115325 is a deficient number, since it is larger than the sum of its proper divisors (12132547).

21115325 is a wasteful number, since it uses less digits than its factorization.

21115325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1602 (or 1590 counting only the distinct ones).

The product of its digits is 300, while the sum is 20.

The square root of 21115325 is about 4595.1414559293. The cubic root of 21115325 is about 276.3965323491.

Adding to 21115325 its reverse (52351112), we get a palindrome (73466437).

The spelling of 21115325 in words is "twenty-one million, one hundred fifteen thousand, three hundred twenty-five".