21363499 has 4 divisors (see below), whose sum is σ = 21379936. Its totient is φ = 21347064.

The previous prime is 21363497. The next prime is 21363593. The reversal of 21363499 is 99436312.

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

It is a cyclic number.

It is not a de Polignac number, because 21363499 - 2¹ = 21363497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21363497) 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, 6084 + ... + 8929.

It is an arithmetic number, because the mean of its divisors is an integer number (5344984).

Almost surely, 2^21363499 is an apocalyptic number.

21363499 is a deficient number, since it is larger than the sum of its proper divisors (16437).

21363499 is a wasteful number, since it uses less digits than its factorization.

21363499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16436.

The product of its digits is 34992, while the sum is 37.

The square root of 21363499 is about 4622.0665291620. The cubic root of 21363499 is about 277.4751713305.

The spelling of 21363499 in words is "twenty-one million, three hundred sixty-three thousand, four hundred ninety-nine".