21993374 has 24 divisors (see below), whose sum is σ = 37575720. Its totient is φ = 9570960.

The previous prime is 21993347. The next prime is 21993401. The reversal of 21993374 is 47339912.

It is an interprime number because it is at equal distance from previous prime (21993347) and next prime (21993401).

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104129 + ... + 104339.

It is an arithmetic number, because the mean of its divisors is an integer number (1565655).

Almost surely, 2^21993374 is an apocalyptic number.

21993374 is a deficient number, since it is larger than the sum of its proper divisors (15582346).

21993374 is a wasteful number, since it uses less digits than its factorization.

21993374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456 (or 245 counting only the distinct ones).

The product of its digits is 40824, while the sum is 38.

The square root of 21993374 is about 4689.7093726584. The cubic root of 21993374 is about 280.1757994642.

The spelling of 21993374 in words is "twenty-one million, nine hundred ninety-three thousand, three hundred seventy-four".