21131325 has 36 divisors (see below), whose sum is σ = 39848640. Its totient is φ = 10674720.

The previous prime is 21131317. The next prime is 21131333. The reversal of 21131325 is 52313112.

It is an interprime number because it is at equal distance from previous prime (21131317) and next prime (21131333).

It is not a de Polignac number, because 21131325 - 2³ = 21131317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21131298 and 21131307.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1804 + ... + 6746.

Almost surely, 2^21131325 is an apocalyptic number.

21131325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21131325 is a deficient number, since it is larger than the sum of its proper divisors (18717315).

21131325 is a wasteful number, since it uses less digits than its factorization.

21131325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4978 (or 4970 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 21131325 is about 4596.8820955078. The cubic root of 21131325 is about 276.4663272806.

Adding to 21131325 its reverse (52313112), we get a palindrome (73444437).

It can be divided in two parts, 211313 and 25, that multiplied together give a palindrome (5282825).

The spelling of 21131325 in words is "twenty-one million, one hundred thirty-one thousand, three hundred twenty-five".