21099392 has 16 divisors (see below), whose sum is σ = 42034200. Its totient is φ = 10549632.

The previous prime is 21099391. The next prime is 21099413. The reversal of 21099392 is 29399012.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21099391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82292 + ... + 82547.

Almost surely, 2^21099392 is an apocalyptic number.

It is an amenable number.

21099392 is a deficient number, since it is larger than the sum of its proper divisors (20934808).

21099392 is an equidigital number, since it uses as much as digits as its factorization.

21099392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164853 (or 164841 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 21099392 is about 4593.4074498133. The cubic root of 21099392 is about 276.3269946384.

The spelling of 21099392 in words is "twenty-one million, ninety-nine thousand, three hundred ninety-two".