21624473 has 8 divisors (see below), whose sum is σ = 23341248. Its totient is φ = 19915344.

The previous prime is 21624469. The next prime is 21624479. The reversal of 21624473 is 37442612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21624473 - 2² = 21624469 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21624479) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4886 + ... + 8192.

It is an arithmetic number, because the mean of its divisors is an integer number (2917656).

Almost surely, 2^21624473 is an apocalyptic number.

It is an amenable number.

21624473 is a deficient number, since it is larger than the sum of its proper divisors (1716775).

21624473 is a wasteful number, since it uses less digits than its factorization.

21624473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3823.

The product of its digits is 8064, while the sum is 29.

The square root of 21624473 is about 4650.2121456983. The cubic root of 21624473 is about 278.6004695812.

The spelling of 21624473 in words is "twenty-one million, six hundred twenty-four thousand, four hundred seventy-three".