647220777993 has 12 divisors (see below), whose sum is σ = 938349830340. Its totient is φ = 429876500256.

The previous prime is 647220777961. The next prime is 647220778031. The reversal of 647220777993 is 399777022746.

647220777993 is a `hidden beast` number, since 6 + 472 + 2 + 0 + 7 + 7 + 79 + 93 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 231160947264 + 416059830729 = 480792^2 + 645027^2 .

It is not a de Polignac number, because 647220777993 - 2⁵ = 647220777961 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 647220777993.

It is not an unprimeable number, because it can be changed into a prime (647220777913) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 133665646 + ... + 133670487.

It is an arithmetic number, because the mean of its divisors is an integer number (78195819195).

Almost surely, 2^647220777993 is an apocalyptic number.

It is an amenable number.

647220777993 is a deficient number, since it is larger than the sum of its proper divisors (291129052347).

647220777993 is a wasteful number, since it uses less digits than its factorization.

647220777993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267336408 (or 267336405 counting only the distinct ones).

The product of its (nonzero) digits is 56010528, while the sum is 63.

The spelling of 647220777993 in words is "six hundred forty-seven billion, two hundred twenty million, seven hundred seventy-seven thousand, nine hundred ninety-three".