21146899 has 4 divisors (see below), whose sum is σ = 21158280. Its totient is φ = 21135520.

The previous prime is 21146891. The next prime is 21146903. The reversal of 21146899 is 99864112.

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 21146899 - 2³ = 21146891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21146891) 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, 2182 + ... + 6859.

It is an arithmetic number, because the mean of its divisors is an integer number (5289570).

Almost surely, 2^21146899 is an apocalyptic number.

21146899 is a deficient number, since it is larger than the sum of its proper divisors (11381).

21146899 is an equidigital number, since it uses as much as digits as its factorization.

21146899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11380.

The product of its digits is 31104, while the sum is 40.

The square root of 21146899 is about 4598.5757577754. The cubic root of 21146899 is about 276.5342300937.

The spelling of 21146899 in words is "twenty-one million, one hundred forty-six thousand, eight hundred ninety-nine".