21840574 has 12 divisors (see below), whose sum is σ = 38109744. Its totient is φ = 9360204.

The previous prime is 21840551. The next prime is 21840583. The reversal of 21840574 is 47504812.

It is a congruent number.

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 5 ways as a sum of consecutive naturals, for example, 111334 + ... + 111529.

It is an arithmetic number, because the mean of its divisors is an integer number (3175812).

Almost surely, 2^21840574 is an apocalyptic number.

21840574 is a deficient number, since it is larger than the sum of its proper divisors (16269170).

21840574 is a wasteful number, since it uses less digits than its factorization.

21840574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222879 (or 222872 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 21840574 is about 4673.3899901463. The cubic root of 21840574 is about 279.5254461639.

The spelling of 21840574 in words is "twenty-one million, eight hundred forty thousand, five hundred seventy-four".