21080899 has 16 divisors (see below), whose sum is σ = 26183680. Its totient is φ = 16562880.

The previous prime is 21080897. The next prime is 21080933. The reversal of 21080899 is 99808012.

It is a cyclic number.

It is not a de Polignac number, because 21080899 - 2¹ = 21080897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21080893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1567 + ... + 6679.

It is an arithmetic number, because the mean of its divisors is an integer number (1636480).

Almost surely, 2^21080899 is an apocalyptic number.

21080899 is a deficient number, since it is larger than the sum of its proper divisors (5102781).

21080899 is a wasteful number, since it uses less digits than its factorization.

21080899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5170.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 21080899 is about 4591.3940148935. The cubic root of 21080899 is about 276.2462401978.

The spelling of 21080899 in words is "twenty-one million, eighty thousand, eight hundred ninety-nine".