21368712 has 64 divisors (see below), whose sum is σ = 55177920. Its totient is φ = 6893568.

The previous prime is 21368707. The next prime is 21368713. The reversal of 21368712 is 21786312.

It is a self number, because there is not a number n which added to its sum of digits gives 21368712.

It is not an unprimeable number, because it can be changed into a prime (21368713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155908 + ... + 156044.

It is an arithmetic number, because the mean of its divisors is an integer number (862155).

Almost surely, 2^21368712 is an apocalyptic number.

It is an amenable number.

21368712 is an abundant number, since it is smaller than the sum of its proper divisors (33809208).

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

21368712 is a wasteful number, since it uses less digits than its factorization.

21368712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310 (or 306 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 21368712 is about 4622.6304200098. The cubic root of 21368712 is about 277.4977388015.

The spelling of 21368712 in words is "twenty-one million, three hundred sixty-eight thousand, seven hundred twelve".