21293099 has 2 divisors, whose sum is σ = 21293100. Its totient is φ = 21293098.

The previous prime is 21293089. The next prime is 21293117. The reversal of 21293099 is 99039212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21293099 is a prime.

It is not a weakly prime, because it can be changed into another prime (21293029) 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 as a sum of consecutive naturals, namely, 10646549 + 10646550.

It is an arithmetic number, because the mean of its divisors is an integer number (10646550).

Almost surely, 2^21293099 is an apocalyptic number.

21293099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21293099 is an equidigital number, since it uses as much as digits as its factorization.

21293099 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21293099 is about 4614.4446036332. Note that the first 3 decimals coincide. The cubic root of 21293099 is about 277.1700442105.

The spelling of 21293099 in words is "twenty-one million, two hundred ninety-three thousand, ninety-nine".