21363239 has 12 divisors (see below), whose sum is σ = 23021400. Its totient is φ = 19769328.

The previous prime is 21363193. The next prime is 21363253. The reversal of 21363239 is 93236312.

It is not a de Polignac number, because 21363239 - 2⁸ = 21362983 is a prime.

It is a super-2 number, since 2×21363239² = 912775961142242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21363289) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41717 + ... + 42225.

It is an arithmetic number, because the mean of its divisors is an integer number (1918450).

Almost surely, 2^21363239 is an apocalyptic number.

21363239 is a deficient number, since it is larger than the sum of its proper divisors (1658161).

21363239 is an equidigital number, since it uses as much as digits as its factorization.

21363239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622 (or 575 counting only the distinct ones).

The product of its digits is 5832, while the sum is 29.

The square root of 21363239 is about 4622.0384031291. The cubic root of 21363239 is about 277.4740456747.

The spelling of 21363239 in words is "twenty-one million, three hundred sixty-three thousand, two hundred thirty-nine".