21693099 has 4 divisors (see below), whose sum is σ = 28924136. Its totient is φ = 14462064.

The previous prime is 21693097. The next prime is 21693101. The reversal of 21693099 is 99039612.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21693097) and next prime (21693101).

It is not a de Polignac number, because 21693099 - 2¹ = 21693097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21693097) 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 3 ways as a sum of consecutive naturals, for example, 3615514 + ... + 3615519.

It is an arithmetic number, because the mean of its divisors is an integer number (7231034).

Almost surely, 2^21693099 is an apocalyptic number.

21693099 is a deficient number, since it is larger than the sum of its proper divisors (7231037).

21693099 is an equidigital number, since it uses as much as digits as its factorization.

21693099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7231036.

The product of its (nonzero) digits is 26244, while the sum is 39.

The square root of 21693099 is about 4657.5851038924. The cubic root of 21693099 is about 278.8948743856.

The spelling of 21693099 in words is "twenty-one million, six hundred ninety-three thousand, ninety-nine".