21325212 has 18 divisors (see below), whose sum is σ = 53905488. Its totient is φ = 7108392.

The previous prime is 21325189. The next prime is 21325217. The reversal of 21325212 is 21252312.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21325217) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 296148 + ... + 296219.

Almost surely, 2^21325212 is an apocalyptic number.

It is an amenable number.

21325212 is an abundant number, since it is smaller than the sum of its proper divisors (32580276).

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

21325212 is a wasteful number, since it uses less digits than its factorization.

21325212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592377 (or 592372 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 21325212 is about 4617.9229097074. The cubic root of 21325212 is about 277.3093114107.

Adding to 21325212 its reverse (21252312), we get a palindrome (42577524).

Subtracting from 21325212 its reverse (21252312), we obtain a square (72900 = 270²).

It can be divided in two parts, 213 and 25212, that added together give a triangular number (25425 = T₂₂₅).

The spelling of 21325212 in words is "twenty-one million, three hundred twenty-five thousand, two hundred twelve".