21867812 has 6 divisors (see below), whose sum is σ = 38268678. Its totient is φ = 10933904.

The previous prime is 21867773. The next prime is 21867821. The reversal of 21867812 is 21876812.

It can be written as a sum of positive squares in only one way, i.e., 20214016 + 1653796 = 4496^2 + 1286^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2733473 + ... + 2733480.

It is an arithmetic number, because the mean of its divisors is an integer number (6378113).

Almost surely, 2^21867812 is an apocalyptic number.

It is an amenable number.

21867812 is a deficient number, since it is larger than the sum of its proper divisors (16400866).

21867812 is a wasteful number, since it uses less digits than its factorization.

21867812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5466957 (or 5466955 counting only the distinct ones).

The product of its digits is 10752, while the sum is 35.

The square root of 21867812 is about 4676.3032408089. The cubic root of 21867812 is about 279.6415992650.

The spelling of 21867812 in words is "twenty-one million, eight hundred sixty-seven thousand, eight hundred twelve".