21647452 has 6 divisors (see below), whose sum is σ = 37883048. Its totient is φ = 10823724.

The previous prime is 21647429. The next prime is 21647453. The reversal of 21647452 is 25474612.

It is a super-2 number, since 2×21647452² = 937224356184608, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21647453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2705928 + ... + 2705935.

Almost surely, 2^21647452 is an apocalyptic number.

It is an amenable number.

21647452 is a deficient number, since it is larger than the sum of its proper divisors (16235596).

21647452 is a wasteful number, since it uses less digits than its factorization.

21647452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5411867 (or 5411865 counting only the distinct ones).

The product of its digits is 13440, while the sum is 31.

The square root of 21647452 is about 4652.6822371617. The cubic root of 21647452 is about 278.6991185190.

The spelling of 21647452 in words is "twenty-one million, six hundred forty-seven thousand, four hundred fifty-two".