621753218377 has 2 divisors, whose sum is σ = 621753218378. Its totient is φ = 621753218376.

The previous prime is 621753218357. The next prime is 621753218431. The reversal of 621753218377 is 773812357126.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 487254257296 + 134498961081 = 698036^2 + 366741^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621753218377 is a prime.

It is not a weakly prime, because it can be changed into another prime (621753218357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310876609188 + 310876609189.

It is an arithmetic number, because the mean of its divisors is an integer number (310876609189).

Almost surely, 2^621753218377 is an apocalyptic number.

It is an amenable number.

621753218377 is a deficient number, since it is larger than the sum of its proper divisors (1).

621753218377 is an equidigital number, since it uses as much as digits as its factorization.

621753218377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2963520, while the sum is 52.

The spelling of 621753218377 in words is "six hundred twenty-one billion, seven hundred fifty-three million, two hundred eighteen thousand, three hundred seventy-seven".