21794440 has 16 divisors (see below), whose sum is σ = 49037580. Its totient is φ = 8717760.

The previous prime is 21794431. The next prime is 21794447. The reversal of 21794440 is 4449712.

It can be written as a sum of positive squares in 2 ways, for example, as 18992164 + 2802276 = 4358^2 + 1674^2 .

It is a super-2 number, since 2×21794440² = 949995229827200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21794447) 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, 272391 + ... + 272470.

Almost surely, 2^21794440 is an apocalyptic number.

21794440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21794440 is an abundant number, since it is smaller than the sum of its proper divisors (27243140).

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

21794440 is a wasteful number, since it uses less digits than its factorization.

21794440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544872 (or 544868 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21794440 is about 4668.4515634201. The cubic root of 21794440 is about 279.3284928932.

The spelling of 21794440 in words is "twenty-one million, seven hundred ninety-four thousand, four hundred forty".