21642824597 has 2 divisors, whose sum is σ = 21642824598. Its totient is φ = 21642824596.

The previous prime is 21642824569. The next prime is 21642824639. The reversal of 21642824597 is 79542824612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12010187281 + 9632637316 = 109591^2 + 98146^2 .

It is a cyclic number.

It is not a de Polignac number, because 21642824597 - 2⁸ = 21642824341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21642824557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10821412298 + 10821412299.

It is an arithmetic number, because the mean of its divisors is an integer number (10821412299).

Almost surely, 2^21642824597 is an apocalyptic number.

It is an amenable number.

21642824597 is a deficient number, since it is larger than the sum of its proper divisors (1).

21642824597 is an equidigital number, since it uses as much as digits as its factorization.

21642824597 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1935360, while the sum is 50.

The spelling of 21642824597 in words is "twenty-one billion, six hundred forty-two million, eight hundred twenty-four thousand, five hundred ninety-seven".