21092999 has 4 divisors (see below), whose sum is σ = 21102336. Its totient is φ = 21083664.

The previous prime is 21092977. The next prime is 21093011. The reversal of 21092999 is 99929012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21092999 - 2¹⁶ = 21027463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21092969) 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, 1082 + ... + 6584.

It is an arithmetic number, because the mean of its divisors is an integer number (5275584).

Almost surely, 2^21092999 is an apocalyptic number.

21092999 is a deficient number, since it is larger than the sum of its proper divisors (9337).

21092999 is an equidigital number, since it uses as much as digits as its factorization.

21092999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9336.

The product of its (nonzero) digits is 26244, while the sum is 41.

The square root of 21092999 is about 4592.7115084664. The cubic root of 21092999 is about 276.2990832982.

The spelling of 21092999 in words is "twenty-one million, ninety-two thousand, nine hundred ninety-nine".