21231325 has 6 divisors (see below), whose sum is σ = 26326874. Its totient is φ = 16985040.

The previous prime is 21231313. The next prime is 21231359. The reversal of 21231325 is 52313212.

It can be written as a sum of positive squares in 3 ways, for example, as 3481956 + 17749369 = 1866^2 + 4213^2 .

It is not a de Polignac number, because 21231325 - 2¹⁷ = 21100253 is a prime.

It is a super-2 number, since 2×21231325² = 901538322511250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 424602 + ... + 424651.

Almost surely, 2^21231325 is an apocalyptic number.

21231325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21231325 is a deficient number, since it is larger than the sum of its proper divisors (5095549).

21231325 is an equidigital number, since it uses as much as digits as its factorization.

21231325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 849263 (or 849258 counting only the distinct ones).

The product of its digits is 360, while the sum is 19.

The square root of 21231325 is about 4607.7461952673. The cubic root of 21231325 is about 276.9017493566.

Adding to 21231325 its reverse (52313212), we get a palindrome (73544537).

The spelling of 21231325 in words is "twenty-one million, two hundred thirty-one thousand, three hundred twenty-five".