21064268 has 6 divisors (see below), whose sum is σ = 36862476. Its totient is φ = 10532132.

The previous prime is 21064261. The next prime is 21064271. The reversal of 21064268 is 86246012.

It is a self number, because there is not a number n which added to its sum of digits gives 21064268.

It is not an unprimeable number, because it can be changed into a prime (21064261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2633030 + ... + 2633037.

It is an arithmetic number, because the mean of its divisors is an integer number (6143746).

Almost surely, 2^21064268 is an apocalyptic number.

It is an amenable number.

21064268 is a deficient number, since it is larger than the sum of its proper divisors (15798208).

21064268 is a wasteful number, since it uses less digits than its factorization.

21064268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5266071 (or 5266069 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 21064268 is about 4589.5825518232. The cubic root of 21064268 is about 276.1735763153.

The spelling of 21064268 in words is "twenty-one million, sixty-four thousand, two hundred sixty-eight".