623421537569 has 2 divisors, whose sum is σ = 623421537570. Its totient is φ = 623421537568.

The previous prime is 623421537559. The next prime is 623421537631. The reversal of 623421537569 is 965735124326.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 583181177569 + 40240360000 = 763663^2 + 200600^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-623421537569 is a prime.

It is a super-2 number, since 2×623421537569² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 623421537569.

It is not a weakly prime, because it can be changed into another prime (623421537509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311710768784 + 311710768785.

It is an arithmetic number, because the mean of its divisors is an integer number (311710768785).

Almost surely, 2^623421537569 is an apocalyptic number.

It is an amenable number.

623421537569 is a deficient number, since it is larger than the sum of its proper divisors (1).

623421537569 is an equidigital number, since it uses as much as digits as its factorization.

623421537569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8164800, while the sum is 53.

The spelling of 623421537569 in words is "six hundred twenty-three billion, four hundred twenty-one million, five hundred thirty-seven thousand, five hundred sixty-nine".