21953212 has 6 divisors (see below), whose sum is σ = 38418128. Its totient is φ = 10976604.

The previous prime is 21953167. The next prime is 21953221. The reversal of 21953212 is 21235912.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2744148 + ... + 2744155.

Almost surely, 2^21953212 is an apocalyptic number.

It is an amenable number.

21953212 is a deficient number, since it is larger than the sum of its proper divisors (16464916).

21953212 is a wasteful number, since it uses less digits than its factorization.

21953212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5488307 (or 5488305 counting only the distinct ones).

The product of its digits is 1080, while the sum is 25.

The square root of 21953212 is about 4685.4254876158. The cubic root of 21953212 is about 280.0051529664.

The spelling of 21953212 in words is "twenty-one million, nine hundred fifty-three thousand, two hundred twelve".