21973836 has 12 divisors (see below), whose sum is σ = 51272312. Its totient is φ = 7324608.

The previous prime is 21973829. The next prime is 21973849. The reversal of 21973836 is 63837912.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21973794 and 21973803.

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 3 ways as a sum of consecutive naturals, for example, 915565 + ... + 915588.

Almost surely, 2^21973836 is an apocalyptic number.

It is an amenable number.

21973836 is an abundant number, since it is smaller than the sum of its proper divisors (29298476).

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

21973836 is a wasteful number, since it uses less digits than its factorization.

21973836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1831160 (or 1831158 counting only the distinct ones).

The product of its digits is 54432, while the sum is 39.

The square root of 21973836 is about 4687.6258383109. The cubic root of 21973836 is about 280.0928093699.

The spelling of 21973836 in words is "twenty-one million, nine hundred seventy-three thousand, eight hundred thirty-six".