647776939 has 2 divisors, whose sum is σ = 647776940. Its totient is φ = 647776938.

The previous prime is 647776919. The next prime is 647776951. The reversal of 647776939 is 939677746.

647776939 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647776939 - 2²⁵ = 614222507 is a prime.

It is a super-2 number, since 2×647776939² = 839229925400419442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (647776919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323888469 + 323888470.

It is an arithmetic number, because the mean of its divisors is an integer number (323888470).

Almost surely, 2^647776939 is an apocalyptic number.

647776939 is a deficient number, since it is larger than the sum of its proper divisors (1).

647776939 is an equidigital number, since it uses as much as digits as its factorization.

647776939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12002256, while the sum is 58.

The square root of 647776939 is about 25451.4624137789. The cubic root of 647776939 is about 865.2504376929.

The spelling of 647776939 in words is "six hundred forty-seven million, seven hundred seventy-six thousand, nine hundred thirty-nine".