21280694 has 8 divisors (see below), whose sum is σ = 32950848. Its totient is φ = 10297080.

The previous prime is 21280691. The next prime is 21280709. The reversal of 21280694 is 49608212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21280694.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21280691) 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, 171557 + ... + 171680.

It is an arithmetic number, because the mean of its divisors is an integer number (4118856).

Almost surely, 2^21280694 is an apocalyptic number.

21280694 is a deficient number, since it is larger than the sum of its proper divisors (11670154).

21280694 is a wasteful number, since it uses less digits than its factorization.

21280694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343270.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21280694 is about 4613.1002590449. The cubic root of 21280694 is about 277.1162088918.

The spelling of 21280694 in words is "twenty-one million, two hundred eighty thousand, six hundred ninety-four".