21994136 has 16 divisors (see below), whose sum is σ = 41313840. Its totient is φ = 10977120.

The previous prime is 21994127. The next prime is 21994139. The reversal of 21994136 is 63149912.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21994096 and 21994105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21994139) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2870 + ... + 7226.

It is an arithmetic number, because the mean of its divisors is an integer number (2582115).

Almost surely, 2^21994136 is an apocalyptic number.

It is an amenable number.

21994136 is a deficient number, since it is larger than the sum of its proper divisors (19319704).

21994136 is a wasteful number, since it uses less digits than its factorization.

21994136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4994 (or 4990 counting only the distinct ones).

The product of its digits is 11664, while the sum is 35.

The square root of 21994136 is about 4689.7906136628. The cubic root of 21994136 is about 280.1790351584.

The spelling of 21994136 in words is "twenty-one million, nine hundred ninety-four thousand, one hundred thirty-six".