648866778787 has 2 divisors, whose sum is σ = 648866778788. Its totient is φ = 648866778786.

The previous prime is 648866778773. The next prime is 648866778797. The reversal of 648866778787 is 787877668846.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 648866778787 - 2²³ = 648858390179 is a prime.

It is a super-2 number, since 2×648866778787² (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 648866778787.

It is not a weakly prime, because it can be changed into another prime (648866778737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324433389393 + 324433389394.

It is an arithmetic number, because the mean of its divisors is an integer number (324433389394).

Almost surely, 2^648866778787 is an apocalyptic number.

648866778787 is a deficient number, since it is larger than the sum of its proper divisors (1).

648866778787 is an equidigital number, since it uses as much as digits as its factorization.

648866778787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8497004544, while the sum is 82.

The spelling of 648866778787 in words is "six hundred forty-eight billion, eight hundred sixty-six million, seven hundred seventy-eight thousand, seven hundred eighty-seven".