21273252 has 216 divisors, whose sum is σ = 71322048. Its totient is φ = 4878720.

The previous prime is 21273191. The next prime is 21273253. The reversal of 21273252 is 25237212.

It is a happy number.

It is a zygodrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21273253) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 924913 + ... + 924935.

Almost surely, 2^21273252 is an apocalyptic number.

21273252 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21273252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35661024).

21273252 is an abundant number, since it is smaller than the sum of its proper divisors (50048796).

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

21273252 is a wasteful number, since it uses less digits than its factorization.

21273252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 59 counting only the distinct ones).

The product of its digits is 1680, while the sum is 24.

The square root of 21273252 is about 4612.2935726166. The cubic root of 21273252 is about 277.0839019994.

The spelling of 21273252 in words is "twenty-one million, two hundred seventy-three thousand, two hundred fifty-two".