21497752 has 8 divisors (see below), whose sum is σ = 40308300. Its totient is φ = 10748872.

The previous prime is 21497731. The next prime is 21497761. The reversal of 21497752 is 25779412.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

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, 1343602 + ... + 1343617.

Almost surely, 2^21497752 is an apocalyptic number.

It is an amenable number.

21497752 is a deficient number, since it is larger than the sum of its proper divisors (18810548).

21497752 is a wasteful number, since it uses less digits than its factorization.

21497752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2687225 (or 2687221 counting only the distinct ones).

The product of its digits is 35280, while the sum is 37.

The square root of 21497752 is about 4636.5668333369. The cubic root of 21497752 is about 278.0551966725.

The spelling of 21497752 in words is "twenty-one million, four hundred ninety-seven thousand, seven hundred fifty-two".