621753218431 has 2 divisors, whose sum is σ = 621753218432. Its totient is φ = 621753218430.

The previous prime is 621753218377. The next prime is 621753218441. The reversal of 621753218431 is 134812357126.

It is a happy number.

621753218431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 621753218431 - 2⁹ = 621753217919 is a prime.

It is a super-2 number, since 2×621753218431² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621753218441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310876609215 + 310876609216.

It is an arithmetic number, because the mean of its divisors is an integer number (310876609216).

Almost surely, 2^621753218431 is an apocalyptic number.

621753218431 is a deficient number, since it is larger than the sum of its proper divisors (1).

621753218431 is an equidigital number, since it uses as much as digits as its factorization.

621753218431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 43.

The spelling of 621753218431 in words is "six hundred twenty-one billion, seven hundred fifty-three million, two hundred eighteen thousand, four hundred thirty-one".