21662493 has 8 divisors (see below), whose sum is σ = 28904928. Its totient is φ = 14430864.

The previous prime is 21662483. The next prime is 21662533. The reversal of 21662493 is 39426612.

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

It is not a de Polignac number, because 21662493 - 2⁴ = 21662477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21662453) 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, 5830 + ... + 8792.

It is an arithmetic number, because the mean of its divisors is an integer number (3613116).

Almost surely, 2^21662493 is an apocalyptic number.

It is an amenable number.

21662493 is a deficient number, since it is larger than the sum of its proper divisors (7242435).

21662493 is a wasteful number, since it uses less digits than its factorization.

21662493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5403.

The product of its digits is 15552, while the sum is 33.

The square root of 21662493 is about 4654.2983359471. The cubic root of 21662493 is about 278.7636517944.

It can be divided in two parts, 21662 and 493, that added together give a triangular number (22155 = T₂₁₀).

The spelling of 21662493 in words is "twenty-one million, six hundred sixty-two thousand, four hundred ninety-three".