21368612 has 6 divisors (see below), whose sum is σ = 37395078. Its totient is φ = 10684304.

The previous prime is 21368591. The next prime is 21368617. The reversal of 21368612 is 21686312.

It can be written as a sum of positive squares in only one way, i.e., 19219456 + 2149156 = 4384^2 + 1466^2 .

It is not an unprimeable number, because it can be changed into a prime (21368617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2671073 + ... + 2671080.

It is an arithmetic number, because the mean of its divisors is an integer number (6232513).

Almost surely, 2^21368612 is an apocalyptic number.

It is an amenable number.

21368612 is a deficient number, since it is larger than the sum of its proper divisors (16026466).

21368612 is a wasteful number, since it uses less digits than its factorization.

21368612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5342157 (or 5342155 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 21368612 is about 4622.6196036447. The cubic root of 21368612 is about 277.4973059284.

The spelling of 21368612 in words is "twenty-one million, three hundred sixty-eight thousand, six hundred twelve".