648285709 has 4 divisors (see below), whose sum is σ = 651867580. Its totient is φ = 644703840.

The previous prime is 648285679. The next prime is 648285767. The reversal of 648285709 is 907582846.

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 342805225 + 305480484 = 18515^2 + 17478^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-648285709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648280709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1790664 + ... + 1791025.

It is an arithmetic number, because the mean of its divisors is an integer number (162966895).

Almost surely, 2^648285709 is an apocalyptic number.

It is an amenable number.

648285709 is a deficient number, since it is larger than the sum of its proper divisors (3581871).

648285709 is a wasteful number, since it uses less digits than its factorization.

648285709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3581870.

The product of its (nonzero) digits is 967680, while the sum is 49.

The square root of 648285709 is about 25461.4553590324. The cubic root of 648285709 is about 865.4769036463.

The spelling of 648285709 in words is "six hundred forty-eight million, two hundred eighty-five thousand, seven hundred nine".