21365197 has 8 divisors (see below), whose sum is σ = 24463296. Its totient is φ = 18278592.

The previous prime is 21365191. The next prime is 21365203. The reversal of 21365197 is 79156312.

It is an interprime number because it is at equal distance from previous prime (21365191) and next prime (21365203).

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

It is a cyclic number.

It is not a de Polignac number, because 21365197 - 2¹¹ = 21363149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1578 + ... + 6724.

It is an arithmetic number, because the mean of its divisors is an integer number (3057912).

Almost surely, 2^21365197 is an apocalyptic number.

It is an amenable number.

21365197 is a deficient number, since it is larger than the sum of its proper divisors (3098099).

21365197 is an equidigital number, since it uses as much as digits as its factorization.

21365197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5747.

The product of its digits is 11340, while the sum is 34.

The square root of 21365197 is about 4622.2502095841. The cubic root of 21365197 is about 277.4825225039.

The spelling of 21365197 in words is "twenty-one million, three hundred sixty-five thousand, one hundred ninety-seven".