21363697 has 4 divisors (see below), whose sum is σ = 21392896. Its totient is φ = 21334500.

The previous prime is 21363659. The next prime is 21363703. The reversal of 21363697 is 79636312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21363697 - 2¹⁵ = 21330929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21363607) 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, 13473 + ... + 14974.

It is an arithmetic number, because the mean of its divisors is an integer number (5348224).

Almost surely, 2^21363697 is an apocalyptic number.

It is an amenable number.

21363697 is a deficient number, since it is larger than the sum of its proper divisors (29199).

21363697 is an equidigital number, since it uses as much as digits as its factorization.

21363697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29198.

The product of its digits is 40824, while the sum is 37.

The square root of 21363697 is about 4622.0879481031. The cubic root of 21363697 is about 277.4760285545.

The spelling of 21363697 in words is "twenty-one million, three hundred sixty-three thousand, six hundred ninety-seven".