21366363 has 4 divisors (see below), whose sum is σ = 28488488. Its totient is φ = 14244240.

The previous prime is 21366343. The next prime is 21366377. The reversal of 21366363 is 36366312.

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

It is a de Polignac number, because none of the positive numbers 2^k-21366363 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21366363.

It is not an unprimeable number, because it can be changed into a prime (21366343) 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 3 ways as a sum of consecutive naturals, for example, 3561058 + ... + 3561063.

It is an arithmetic number, because the mean of its divisors is an integer number (7122122).

Almost surely, 2^21366363 is an apocalyptic number.

21366363 is a deficient number, since it is larger than the sum of its proper divisors (7122125).

21366363 is an equidigital number, since it uses as much as digits as its factorization.

21366363 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7122124.

The product of its digits is 11664, while the sum is 30.

The square root of 21366363 is about 4622.3763369072. The cubic root of 21366363 is about 277.4875702573.

The spelling of 21366363 in words is "twenty-one million, three hundred sixty-six thousand, three hundred sixty-three".