621698531647 has 2 divisors, whose sum is σ = 621698531648. Its totient is φ = 621698531646.

The previous prime is 621698531563. The next prime is 621698531717. The reversal of 621698531647 is 746135896126.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621698531647 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 621698531591 and 621698531600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621698531747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310849265823 + 310849265824.

It is an arithmetic number, because the mean of its divisors is an integer number (310849265824).

Almost surely, 2^621698531647 is an apocalyptic number.

621698531647 is a deficient number, since it is larger than the sum of its proper divisors (1).

621698531647 is an equidigital number, since it uses as much as digits as its factorization.

621698531647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13063680, while the sum is 58.

The spelling of 621698531647 in words is "six hundred twenty-one billion, six hundred ninety-eight million, five hundred thirty-one thousand, six hundred forty-seven".