21430647 has 12 divisors (see below), whose sum is σ = 35377680. Its totient is φ = 12246048.

The previous prime is 21430639. The next prime is 21430667. The reversal of 21430647 is 74603412.

21430647 is a `hidden beast` number, since 2 + 14 + 3 + 0 + 647 = 666.

It is not a de Polignac number, because 21430647 - 2³ = 21430639 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21430647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430627) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 170022 + ... + 170147.

It is an arithmetic number, because the mean of its divisors is an integer number (2948140).

Almost surely, 2^21430647 is an apocalyptic number.

21430647 is a deficient number, since it is larger than the sum of its proper divisors (13947033).

21430647 is a wasteful number, since it uses less digits than its factorization.

21430647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340182 (or 340179 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 21430647 is about 4629.3246807715. The cubic root of 21430647 is about 277.7655796895.

The spelling of 21430647 in words is "twenty-one million, four hundred thirty thousand, six hundred forty-seven".