621001916819 has 2 divisors, whose sum is σ = 621001916820. Its totient is φ = 621001916818.

The previous prime is 621001916813. The next prime is 621001916863. The reversal of 621001916819 is 918619100126.

It is an a-pointer prime, because the next prime (621001916863) can be obtained adding 621001916819 to its sum of digits (44).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621001916819 is a prime.

It is a super-2 number, since 2×621001916819² (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 621001916819.

It is not a weakly prime, because it can be changed into another prime (621001916813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310500958409 + 310500958410.

It is an arithmetic number, because the mean of its divisors is an integer number (310500958410).

Almost surely, 2^621001916819 is an apocalyptic number.

621001916819 is a deficient number, since it is larger than the sum of its proper divisors (1).

621001916819 is an equidigital number, since it uses as much as digits as its factorization.

621001916819 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 44.

The spelling of 621001916819 in words is "six hundred twenty-one billion, one million, nine hundred sixteen thousand, eight hundred nineteen".