21993192 has 48 divisors (see below), whose sum is σ = 64149540. Its totient is φ = 6766848.

The previous prime is 21993187. The next prime is 21993211. The reversal of 21993192 is 29139912.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21958596 + 34596 = 4686^2 + 186^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10813 + ... + 12684.

Almost surely, 2^21993192 is an apocalyptic number.

It is an amenable number.

21993192 is an abundant number, since it is smaller than the sum of its proper divisors (42156348).

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

21993192 is a wasteful number, since it uses less digits than its factorization.

21993192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23522 (or 23515 counting only the distinct ones).

The product of its digits is 8748, while the sum is 36.

The square root of 21993192 is about 4689.6899684307. The cubic root of 21993192 is about 280.1750266233.

The spelling of 21993192 in words is "twenty-one million, nine hundred ninety-three thousand, one hundred ninety-two".