21716072597 has 4 divisors (see below), whose sum is σ = 22302993516. Its totient is φ = 21129151680.

The previous prime is 21716072551. The next prime is 21716072641. The reversal of 21716072597 is 79527061712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 20955747121 + 760325476 = 144761^2 + 27574^2 .

It is a cyclic number.

It is not a de Polignac number, because 21716072597 - 2⁶ = 21716072533 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 (21716072297) 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, 293460404 + ... + 293460477.

It is an arithmetic number, because the mean of its divisors is an integer number (5575748379).

Almost surely, 2^21716072597 is an apocalyptic number.

It is an amenable number.

21716072597 is a deficient number, since it is larger than the sum of its proper divisors (586920919).

21716072597 is an equidigital number, since it uses as much as digits as its factorization.

21716072597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586920918.

The product of its (nonzero) digits is 370440, while the sum is 47.

The spelling of 21716072597 in words is "twenty-one billion, seven hundred sixteen million, seventy-two thousand, five hundred ninety-seven".