647499891979 has 2 divisors, whose sum is σ = 647499891980. Its totient is φ = 647499891978.

The previous prime is 647499891887. The next prime is 647499892033. The reversal of 647499891979 is 979198994746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647499891979 - 2¹¹ = 647499889931 is a prime.

It is a super-2 number, since 2×647499891979² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (647499892979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323749945989 + 323749945990.

It is an arithmetic number, because the mean of its divisors is an integer number (323749945990).

Almost surely, 2^647499891979 is an apocalyptic number.

647499891979 is a deficient number, since it is larger than the sum of its proper divisors (1).

647499891979 is an equidigital number, since it uses as much as digits as its factorization.

647499891979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2222131968, while the sum is 82.

The spelling of 647499891979 in words is "six hundred forty-seven billion, four hundred ninety-nine million, eight hundred ninety-one thousand, nine hundred seventy-nine".