21994396 has 24 divisors (see below), whose sum is σ = 41002416. Its totient is φ = 10287360.

The previous prime is 21994393. The next prime is 21994403. The reversal of 21994396 is 69349912.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21994393) 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, 11415 + ... + 13201.

It is an arithmetic number, because the mean of its divisors is an integer number (1708434).

Almost surely, 2^21994396 is an apocalyptic number.

It is an amenable number.

21994396 is a deficient number, since it is larger than the sum of its proper divisors (19008020).

21994396 is a wasteful number, since it uses less digits than its factorization.

21994396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1989 (or 1987 counting only the distinct ones).

The product of its digits is 104976, while the sum is 43.

The square root of 21994396 is about 4689.8183333686. The cubic root of 21994396 is about 280.1801391839.

The spelling of 21994396 in words is "twenty-one million, nine hundred ninety-four thousand, three hundred ninety-six".