2643687947 has 2 divisors, whose sum is σ = 2643687948. Its totient is φ = 2643687946.

The previous prime is 2643687923. The next prime is 2643687961. The reversal of 2643687947 is 7497863462.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2643687947 - 2⁸ = 2643687691 is a prime.

It is a super-2 number, since 2×2643687947² = 13978171922226149618, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2643687892 and 2643687901.

It is not a weakly prime, because it can be changed into another prime (2643687547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321843973 + 1321843974.

It is an arithmetic number, because the mean of its divisors is an integer number (1321843974).

Almost surely, 2^2643687947 is an apocalyptic number.

2643687947 is a deficient number, since it is larger than the sum of its proper divisors (1).

2643687947 is an equidigital number, since it uses as much as digits as its factorization.

2643687947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12192768, while the sum is 56.

The square root of 2643687947 is about 51416.8060754458. The cubic root of 2643687947 is about 1382.7279140984.

The spelling of 2643687947 in words is "two billion, six hundred forty-three million, six hundred eighty-seven thousand, nine hundred forty-seven".