21368073 has 4 divisors (see below), whose sum is σ = 28490768. Its totient is φ = 14245380.

The previous prime is 21368069. The next prime is 21368077. The reversal of 21368073 is 37086312.

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 an interprime number because it is at equal distance from previous prime (21368069) and next prime (21368077).

It is not a de Polignac number, because 21368073 - 2² = 21368069 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 21368073.

It is not an unprimeable number, because it can be changed into a prime (21368077) 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, 3561343 + ... + 3561348.

It is an arithmetic number, because the mean of its divisors is an integer number (7122692).

Almost surely, 2^21368073 is an apocalyptic number.

It is an amenable number.

21368073 is a deficient number, since it is larger than the sum of its proper divisors (7122695).

21368073 is an equidigital number, since it uses as much as digits as its factorization.

21368073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7122694.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 21368073 is about 4622.5613030008. The cubic root of 21368073 is about 277.4949727196.

It can be divided in two parts, 213 and 68073, that added together give a palindrome (68286).

The spelling of 21368073 in words is "twenty-one million, three hundred sixty-eight thousand, seventy-three".