647891513693 has 2 divisors, whose sum is σ = 647891513694. Its totient is φ = 647891513692.

The previous prime is 647891513651. The next prime is 647891513767. The reversal of 647891513693 is 396315198746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 509300604409 + 138590909284 = 713653^2 + 372278^2 .

It is a cyclic number.

It is not a de Polignac number, because 647891513693 - 2¹⁸ = 647891251549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647891516693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323945756846 + 323945756847.

It is an arithmetic number, because the mean of its divisors is an integer number (323945756847).

Almost surely, 2^647891513693 is an apocalyptic number.

It is an amenable number.

647891513693 is a deficient number, since it is larger than the sum of its proper divisors (1).

647891513693 is an equidigital number, since it uses as much as digits as its factorization.

647891513693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29393280, while the sum is 62.

The spelling of 647891513693 in words is "six hundred forty-seven billion, eight hundred ninety-one million, five hundred thirteen thousand, six hundred ninety-three".