647580785 has 4 divisors (see below), whose sum is σ = 777096948. Its totient is φ = 518064624.

The previous prime is 647580763. The next prime is 647580803. The reversal of 647580785 is 587085746.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 237437281 + 410143504 = 15409^2 + 20252^2 .

It is a cyclic number.

It is not a de Polignac number, because 647580785 - 2¹⁰ = 647579761 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64758074 + ... + 64758083.

It is an arithmetic number, because the mean of its divisors is an integer number (194274237).

Almost surely, 2^647580785 is an apocalyptic number.

It is an amenable number.

647580785 is a deficient number, since it is larger than the sum of its proper divisors (129516163).

647580785 is a wasteful number, since it uses less digits than its factorization.

647580785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129516162.

The product of its (nonzero) digits is 1881600, while the sum is 50.

The square root of 647580785 is about 25447.6086302819. The cubic root of 647580785 is about 865.1630930849.

The spelling of 647580785 in words is "six hundred forty-seven million, five hundred eighty thousand, seven hundred eighty-five".