21899403 has 12 divisors (see below), whose sum is σ = 32804408. Its totient is φ = 14599440.

The previous prime is 21899393. The next prime is 21899407. The reversal of 21899403 is 30499812.

It is not a de Polignac number, because 21899403 - 2⁴ = 21899387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21899407) 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 11 ways as a sum of consecutive naturals, for example, 44818 + ... + 45303.

Almost surely, 2^21899403 is an apocalyptic number.

21899403 is a deficient number, since it is larger than the sum of its proper divisors (10905005).

21899403 is an frugal number, since it uses more digits than its factorization.

21899403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90136 (or 90124 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 21899403 is about 4679.6797967382. The cubic root of 21899403 is about 279.7761944580.

The spelling of 21899403 in words is "twenty-one million, eight hundred ninety-nine thousand, four hundred three".