21940264 has 8 divisors (see below), whose sum is σ = 41138010. Its totient is φ = 10970128.

The previous prime is 21940241. The next prime is 21940267. The reversal of 21940264 is 46204912.

It can be written as a sum of positive squares in only one way, i.e., 15539364 + 6400900 = 3942^2 + 2530^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21940267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1371259 + ... + 1371274.

Almost surely, 2^21940264 is an apocalyptic number.

It is an amenable number.

21940264 is a deficient number, since it is larger than the sum of its proper divisors (19197746).

21940264 is a wasteful number, since it uses less digits than its factorization.

21940264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742539 (or 2742535 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 21940264 is about 4684.0435523167. The cubic root of 21940264 is about 279.9500931460.

The spelling of 21940264 in words is "twenty-one million, nine hundred forty thousand, two hundred sixty-four".