21633457 has 8 divisors (see below), whose sum is σ = 22838400. Its totient is φ = 20435184.

The previous prime is 21633427. The next prime is 21633499. The reversal of 21633457 is 75433612.

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

It is not a de Polignac number, because 21633457 - 2⁷ = 21633329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21633427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5928 + ... + 8854.

It is an arithmetic number, because the mean of its divisors is an integer number (2854800).

Almost surely, 2^21633457 is an apocalyptic number.

It is an amenable number.

21633457 is a deficient number, since it is larger than the sum of its proper divisors (1204943).

21633457 is a wasteful number, since it uses less digits than its factorization.

21633457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3335.

The product of its digits is 15120, while the sum is 31.

The square root of 21633457 is about 4651.1780228239. The cubic root of 21633457 is about 278.6390462451.

The spelling of 21633457 in words is "twenty-one million, six hundred thirty-three thousand, four hundred fifty-seven".