21277968 has 20 divisors (see below), whose sum is σ = 54968208. Its totient is φ = 7092640.

The previous prime is 21277933. The next prime is 21277969. The reversal of 21277968 is 86977212.

It is not an unprimeable number, because it can be changed into a prime (21277969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221598 + ... + 221693.

Almost surely, 2^21277968 is an apocalyptic number.

It is an amenable number.

21277968 is an abundant number, since it is smaller than the sum of its proper divisors (33690240).

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

21277968 is a wasteful number, since it uses less digits than its factorization.

21277968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443302 (or 443296 counting only the distinct ones).

The product of its digits is 84672, while the sum is 42.

The square root of 21277968 is about 4612.8047866781. The cubic root of 21277968 is about 277.1043757714.

The spelling of 21277968 in words is "twenty-one million, two hundred seventy-seven thousand, nine hundred sixty-eight".