647670091 has 2 divisors, whose sum is σ = 647670092. Its totient is φ = 647670090.

The previous prime is 647670061. The next prime is 647670139. The reversal of 647670091 is 190076746.

647670091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 647670091 - 2²³ = 639281483 is a prime.

It is not a weakly prime, because it can be changed into another prime (647670061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323835045 + 323835046.

It is an arithmetic number, because the mean of its divisors is an integer number (323835046).

Almost surely, 2^647670091 is an apocalyptic number.

647670091 is a deficient number, since it is larger than the sum of its proper divisors (1).

647670091 is an equidigital number, since it uses as much as digits as its factorization.

647670091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 647670091 is about 25449.3632729780. The cubic root of 647670091 is about 865.2028619732.

It can be divided in two parts, 6476 and 70091, that added together give a palindrome (76567).

The spelling of 647670091 in words is "six hundred forty-seven million, six hundred seventy thousand, ninety-one".