21845597 has 2 divisors, whose sum is σ = 21845598. Its totient is φ = 21845596.

The previous prime is 21845563. The next prime is 21845627. The reversal of 21845597 is 79554812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19175641 + 2669956 = 4379^2 + 1634^2 .

It is a cyclic number.

It is not a de Polignac number, because 21845597 - 2⁶ = 21845533 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21845507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10922798 + 10922799.

It is an arithmetic number, because the mean of its divisors is an integer number (10922799).

Almost surely, 2^21845597 is an apocalyptic number.

It is an amenable number.

21845597 is a deficient number, since it is larger than the sum of its proper divisors (1).

21845597 is an equidigital number, since it uses as much as digits as its factorization.

21845597 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 41.

The square root of 21845597 is about 4673.9273635777. The cubic root of 21845597 is about 279.5468733891.

The spelling of 21845597 in words is "twenty-one million, eight hundred forty-five thousand, five hundred ninety-seven".