21732458 has 16 divisors (see below), whose sum is σ = 36390816. Its totient is φ = 9648240.

The previous prime is 21732439. The next prime is 21732481. The reversal of 21732458 is 85423712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10541 + ... + 12432.

It is an arithmetic number, because the mean of its divisors is an integer number (2274426).

Almost surely, 2^21732458 is an apocalyptic number.

21732458 is a deficient number, since it is larger than the sum of its proper divisors (14658358).

21732458 is a wasteful number, since it uses less digits than its factorization.

21732458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23029.

The product of its digits is 13440, while the sum is 32.

The square root of 21732458 is about 4661.8084473732. The cubic root of 21732458 is about 279.0634439893.

The spelling of 21732458 in words is "twenty-one million, seven hundred thirty-two thousand, four hundred fifty-eight".