647831825 has 12 divisors (see below), whose sum is σ = 810423948. Its totient is φ = 513676800.

The previous prime is 647831803. The next prime is 647831839. The reversal of 647831825 is 528138746.

It can be written as a sum of positive squares in 6 ways, for example, as 138697729 + 509134096 = 11777^2 + 22564^2 .

It is a de Polignac number, because none of the positive numbers 2^k-647831825 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 111836 + ... + 117485.

It is an arithmetic number, because the mean of its divisors is an integer number (67535329).

Almost surely, 2^647831825 is an apocalyptic number.

It is an amenable number.

647831825 is a deficient number, since it is larger than the sum of its proper divisors (162592123).

647831825 is a wasteful number, since it uses less digits than its factorization.

647831825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229444 (or 229439 counting only the distinct ones).

The product of its digits is 322560, while the sum is 44.

The square root of 647831825 is about 25452.5406393939. The cubic root of 647831825 is about 865.2748744969.

The spelling of 647831825 in words is "six hundred forty-seven million, eight hundred thirty-one thousand, eight hundred twenty-five".