647397091 has 8 divisors (see below), whose sum is σ = 706507200. Its totient is φ = 588329640.

The previous prime is 647397071. The next prime is 647397133. The reversal of 647397091 is 190793746.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 647397091 - 2⁹ = 647396579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647397041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26820 + ... + 44878.

It is an arithmetic number, because the mean of its divisors is an integer number (88313400).

Almost surely, 2^647397091 is an apocalyptic number.

647397091 is a deficient number, since it is larger than the sum of its proper divisors (59110109).

647397091 is a wasteful number, since it uses less digits than its factorization.

647397091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21329.

The product of its (nonzero) digits is 285768, while the sum is 46.

The square root of 647397091 is about 25443.9991157051. Note that the first 3 decimals coincide. The cubic root of 647397091 is about 865.0812807446.

The spelling of 647397091 in words is "six hundred forty-seven million, three hundred ninety-seven thousand, ninety-one".