21994265 has 16 divisors (see below), whose sum is σ = 26989200. Its totient is φ = 17203200.

The previous prime is 21994237. The next prime is 21994319. The reversal of 21994265 is 56249912.

It can be written as a sum of positive squares in 8 ways, for example, as 1373584 + 20620681 = 1172^2 + 4541^2 .

It is not a de Polignac number, because 21994265 - 2¹² = 21990169 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48761 + ... + 49209.

It is an arithmetic number, because the mean of its divisors is an integer number (1686825).

Almost surely, 2^21994265 is an apocalyptic number.

It is an amenable number.

21994265 is a deficient number, since it is larger than the sum of its proper divisors (4994935).

21994265 is a wasteful number, since it uses less digits than its factorization.

21994265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652.

The product of its digits is 38880, while the sum is 38.

The square root of 21994265 is about 4689.8043669219. The cubic root of 21994265 is about 280.1795829260.

The spelling of 21994265 in words is "twenty-one million, nine hundred ninety-four thousand, two hundred sixty-five".