21463903 has 4 divisors (see below), whose sum is σ = 21476520. Its totient is φ = 21451288.

The previous prime is 21463847. The next prime is 21463909. The reversal of 21463903 is 30936412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21463903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21463909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3268 + ... + 7321.

It is an arithmetic number, because the mean of its divisors is an integer number (5369130).

Almost surely, 2^21463903 is an apocalyptic number.

21463903 is a deficient number, since it is larger than the sum of its proper divisors (12617).

21463903 is a wasteful number, since it uses less digits than its factorization.

21463903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12616.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 21463903 is about 4632.9151729769. The cubic root of 21463903 is about 277.9091839721.

It can be divided in two parts, 21463 and 903, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 21463903 in words is "twenty-one million, four hundred sixty-three thousand, nine hundred three".