621923717 has 2 divisors, whose sum is σ = 621923718. Its totient is φ = 621923716.

The previous prime is 621923689. The next prime is 621923741. The reversal of 621923717 is 717329126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 598585156 + 23338561 = 24466^2 + 4831^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621923717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621923747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310961858 + 310961859.

It is an arithmetic number, because the mean of its divisors is an integer number (310961859).

Almost surely, 2^621923717 is an apocalyptic number.

It is an amenable number.

621923717 is a deficient number, since it is larger than the sum of its proper divisors (1).

621923717 is an equidigital number, since it uses as much as digits as its factorization.

621923717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752, while the sum is 38.

The square root of 621923717 is about 24938.3984449684. The cubic root of 621923717 is about 853.5829002132.

The spelling of 621923717 in words is "six hundred twenty-one million, nine hundred twenty-three thousand, seven hundred seventeen".