21031252 has 36 divisors (see below), whose sum is σ = 42602560. Its totient is φ = 9052560.

The previous prime is 21031229. The next prime is 21031253. The reversal of 21031252 is 25213012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031253) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8053 + ... + 10339.

Almost surely, 2^21031252 is an apocalyptic number.

21031252 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21031252 is an abundant number, since it is smaller than the sum of its proper divisors (21571308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21031252 is a wasteful number, since it uses less digits than its factorization.

21031252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2332 (or 2319 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21031252 is about 4585.9843000167. The cubic root of 21031252 is about 276.0292099590.

Adding to 21031252 its reverse (25213012), we get a palindrome (46244264).

The spelling of 21031252 in words is "twenty-one million, thirty-one thousand, two hundred fifty-two".