21263983 has 24 divisors (see below), whose sum is σ = 25347168. Its totient is φ = 17696448.

The previous prime is 21263959. The next prime is 21263987. The reversal of 21263983 is 38936212.

It is a happy number.

It is not a de Polignac number, because 21263983 - 2⁹ = 21263471 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 (21263987) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 107841 + ... + 108037.

It is an arithmetic number, because the mean of its divisors is an integer number (1056132).

Almost surely, 2^21263983 is an apocalyptic number.

21263983 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21263983 is a deficient number, since it is larger than the sum of its proper divisors (4083185).

21263983 is a wasteful number, since it uses less digits than its factorization.

21263983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271 (or 252 counting only the distinct ones).

The product of its digits is 15552, while the sum is 34.

The square root of 21263983 is about 4611.2886485233. The cubic root of 21263983 is about 277.0436532748.

The spelling of 21263983 in words is "twenty-one million, two hundred sixty-three thousand, nine hundred eighty-three".