21819365 has 8 divisors (see below), whose sum is σ = 26552448. Its totient is φ = 17209360.

The previous prime is 21819337. The next prime is 21819383. The reversal of 21819365 is 56391812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21819365 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30377 + ... + 31086.

It is an arithmetic number, because the mean of its divisors is an integer number (3319056).

Almost surely, 2^21819365 is an apocalyptic number.

It is an amenable number.

21819365 is a deficient number, since it is larger than the sum of its proper divisors (4733083).

21819365 is an equidigital number, since it uses as much as digits as its factorization.

21819365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61539.

The product of its digits is 12960, while the sum is 35.

The square root of 21819365 is about 4671.1203152991. The cubic root of 21819365 is about 279.4349361002.

The spelling of 21819365 in words is "twenty-one million, eight hundred nineteen thousand, three hundred sixty-five".