21277672 has 32 divisors (see below), whose sum is σ = 43381800. Its totient is φ = 9725184.

The previous prime is 21277667. The next prime is 21277679. The reversal of 21277672 is 27677212.

It can be written as a sum of positive squares in 4 ways, for example, as 17690436 + 3587236 = 4206^2 + 1894^2 .

It is not an unprimeable number, because it can be changed into a prime (21277679) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10398 + ... + 12274.

Almost surely, 2^21277672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21277672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21690900).

21277672 is an abundant number, since it is smaller than the sum of its proper divisors (22104128).

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

21277672 is a wasteful number, since it uses less digits than its factorization.

21277672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2005 (or 2001 counting only the distinct ones).

The product of its digits is 16464, while the sum is 34.

The square root of 21277672 is about 4612.7727019657. The cubic root of 21277672 is about 277.1030908230.

The spelling of 21277672 in words is "twenty-one million, two hundred seventy-seven thousand, six hundred seventy-two".