21936458 has 4 divisors (see below), whose sum is σ = 32904690. Its totient is φ = 10968228.

The previous prime is 21936419. The next prime is 21936463. The reversal of 21936458 is 85463912.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12652249 + 9284209 = 3557^2 + 3047^2 .

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 as a sum of consecutive naturals, namely, 5484113 + ... + 5484116.

Almost surely, 2^21936458 is an apocalyptic number.

21936458 is a deficient number, since it is larger than the sum of its proper divisors (10968232).

21936458 is a wasteful number, since it uses less digits than its factorization.

21936458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10968231.

The product of its digits is 51840, while the sum is 38.

The square root of 21936458 is about 4683.6372617870. The cubic root of 21936458 is about 279.9339044670.

The spelling of 21936458 in words is "twenty-one million, nine hundred thirty-six thousand, four hundred fifty-eight".