21999936 has 56 divisors (see below), whose sum is σ = 66527680. Its totient is φ = 6285312.

The previous prime is 21999917. The next prime is 21999973. The reversal of 21999936 is 63999912.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6841 + ... + 9528.

Almost surely, 2^21999936 is an apocalyptic number.

It is an amenable number.

21999936 is an abundant number, since it is smaller than the sum of its proper divisors (44527744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21999936 is a wasteful number, since it uses less digits than its factorization.

21999936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16391 (or 16381 counting only the distinct ones).

The product of its digits is 236196, while the sum is 48.

The square root of 21999936 is about 4690.4089373955. The cubic root of 21999936 is about 280.2036613524.

The spelling of 21999936 in words is "twenty-one million, nine hundred ninety-nine thousand, nine hundred thirty-six".