21866793 has 32 divisors (see below), whose sum is σ = 32659200. Its totient is φ = 12929280.

The previous prime is 21866773. The next prime is 21866809. The reversal of 21866793 is 39766812.

It is a happy number.

It is not a de Polignac number, because 21866793 - 2⁶ = 21866729 is a prime.

It is a super-2 number, since 2×21866793² = 956313272209698, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21866753) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 146683 + ... + 146831.

It is an arithmetic number, because the mean of its divisors is an integer number (1020600).

Almost surely, 2^21866793 is an apocalyptic number.

It is an amenable number.

21866793 is a deficient number, since it is larger than the sum of its proper divisors (10792407).

21866793 is a wasteful number, since it uses less digits than its factorization.

21866793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289.

The product of its digits is 108864, while the sum is 42.

The square root of 21866793 is about 4676.1942859552. The cubic root of 21866793 is about 279.6372556020.

The spelling of 21866793 in words is "twenty-one million, eight hundred sixty-six thousand, seven hundred ninety-three".