21753396 has 36 divisors (see below), whose sum is σ = 62843872. Its totient is φ = 6215184.

The previous prime is 21753367. The next prime is 21753409. The reversal of 21753396 is 69335712.

21753396 is a `hidden beast` number, since 217 + 53 + 396 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21753396.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42910 + ... + 43413.

Almost surely, 2^21753396 is an apocalyptic number.

It is an amenable number.

21753396 is an abundant number, since it is smaller than the sum of its proper divisors (41090476).

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

21753396 is a wasteful number, since it uses less digits than its factorization.

21753396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86340 (or 86335 counting only the distinct ones).

The product of its digits is 34020, while the sum is 36.

The square root of 21753396 is about 4664.0536017503. The cubic root of 21753396 is about 279.1530358633.

The spelling of 21753396 in words is "twenty-one million, seven hundred fifty-three thousand, three hundred ninety-six".