764980781 has 2 divisors, whose sum is σ = 764980782. Its totient is φ = 764980780.

The previous prime is 764980729. The next prime is 764980787. The reversal of 764980781 is 187089467.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 565012900 + 199967881 = 23770^2 + 14141^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-764980781 is a prime.

It is a super-2 number, since 2×764980781² = 1170391190598739922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (764980787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 382490390 + 382490391.

It is an arithmetic number, because the mean of its divisors is an integer number (382490391).

Almost surely, 2^764980781 is an apocalyptic number.

It is an amenable number.

764980781 is a deficient number, since it is larger than the sum of its proper divisors (1).

764980781 is an equidigital number, since it uses as much as digits as its factorization.

764980781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 677376, while the sum is 50.

The square root of 764980781 is about 27658.2859374908. The cubic root of 764980781 is about 914.5697683746.

The spelling of 764980781 in words is "seven hundred sixty-four million, nine hundred eighty thousand, seven hundred eighty-one".