21675903 has 16 divisors (see below), whose sum is σ = 30622080. Its totient is φ = 13600224.

The previous prime is 21675893. The next prime is 21675917. The reversal of 21675903 is 30957612.

It is not a de Polignac number, because 21675903 - 2²⁴ = 4898687 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21695903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8125 + ... + 10457.

It is an arithmetic number, because the mean of its divisors is an integer number (1913880).

Almost surely, 2^21675903 is an apocalyptic number.

21675903 is a deficient number, since it is larger than the sum of its proper divisors (8946177).

21675903 is a wasteful number, since it uses less digits than its factorization.

21675903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518.

The product of its (nonzero) digits is 11340, while the sum is 33.

The square root of 21675903 is about 4655.7387168955. The cubic root of 21675903 is about 278.8211620952.

It can be divided in two parts, 21675 and 903, that added together give a triangular number (22578 = T₂₁₂).

The spelling of 21675903 in words is "twenty-one million, six hundred seventy-five thousand, nine hundred three".