647719531 has 2 divisors, whose sum is σ = 647719532. Its totient is φ = 647719530.

The previous prime is 647719511. The next prime is 647719543. The reversal of 647719531 is 135917746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647719531 - 2⁷ = 647719403 is a prime.

It is a super-2 number, since 2×647719531² = 839081181677719922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (647719511) 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, 323859765 + 323859766.

It is an arithmetic number, because the mean of its divisors is an integer number (323859766).

Almost surely, 2^647719531 is an apocalyptic number.

647719531 is a deficient number, since it is larger than the sum of its proper divisors (1).

647719531 is an equidigital number, since it uses as much as digits as its factorization.

647719531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 43.

The square root of 647719531 is about 25450.3345950500. The cubic root of 647719531 is about 865.2248765460.

The spelling of 647719531 in words is "six hundred forty-seven million, seven hundred nineteen thousand, five hundred thirty-one".