65778513937 has 2 divisors, whose sum is σ = 65778513938. Its totient is φ = 65778513936.

The previous prime is 65778513917. The next prime is 65778513971. The reversal of 65778513937 is 73931587756.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60026960016 + 5751553921 = 245004^2 + 75839^2 .

It is a cyclic number.

It is not a de Polignac number, because 65778513937 - 2¹⁹ = 65777989649 is a prime.

It is not a weakly prime, because it can be changed into another prime (65778513917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32889256968 + 32889256969.

It is an arithmetic number, because the mean of its divisors is an integer number (32889256969).

Almost surely, 2^65778513937 is an apocalyptic number.

It is an amenable number.

65778513937 is a deficient number, since it is larger than the sum of its proper divisors (1).

65778513937 is an equidigital number, since it uses as much as digits as its factorization.

65778513937 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33339600, while the sum is 61.

The spelling of 65778513937 in words is "sixty-five billion, seven hundred seventy-eight million, five hundred thirteen thousand, nine hundred thirty-seven".