647279291 has 2 divisors, whose sum is σ = 647279292. Its totient is φ = 647279290.

The previous prime is 647279207. The next prime is 647279293. The reversal of 647279291 is 192972746.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647279291 is a prime.

Together with 647279293, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (647279293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323639645 + 323639646.

It is an arithmetic number, because the mean of its divisors is an integer number (323639646).

Almost surely, 2^647279291 is an apocalyptic number.

647279291 is a deficient number, since it is larger than the sum of its proper divisors (1).

647279291 is an equidigital number, since it uses as much as digits as its factorization.

647279291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 381024, while the sum is 47.

The square root of 647279291 is about 25441.6841227148. The cubic root of 647279291 is about 865.0288076654.

The spelling of 647279291 in words is "six hundred forty-seven million, two hundred seventy-nine thousand, two hundred ninety-one".