21873699 has 8 divisors (see below), whose sum is σ = 32405520. Its totient is φ = 14582448.

The previous prime is 21873673. The next prime is 21873707. The reversal of 21873699 is 99637812.

It is not a de Polignac number, because 21873699 - 2¹⁷ = 21742627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21873629) 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 7 ways as a sum of consecutive naturals, for example, 405042 + ... + 405095.

It is an arithmetic number, because the mean of its divisors is an integer number (4050690).

Almost surely, 2^21873699 is an apocalyptic number.

21873699 is a deficient number, since it is larger than the sum of its proper divisors (10531821).

21873699 is an equidigital number, since it uses as much as digits as its factorization.

21873699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810146 (or 810140 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 21873699 is about 4676.9326486491. The cubic root of 21873699 is about 279.6666909749. Note that the first 4 decimals are identical.

It can be divided in two parts, 2187 and 3699, that added together give a triangular number (5886 = T₁₀₈).

The spelling of 21873699 in words is "twenty-one million, eight hundred seventy-three thousand, six hundred ninety-nine".