847664081 has 32 divisors (see below), whose sum is σ = 1036177920. Its totient is φ = 683424000.

The previous prime is 847664071. The next prime is 847664099. The reversal of 847664081 is 180466748.

847664081 = 1909² + 1910² + ... + 2117².

It is a cyclic number.

It is not a de Polignac number, because 847664081 - 2¹⁰ = 847663057 is a prime.

It is a super-2 number, since 2×847664081² = 1437068788435149122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (847664071) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 806006 + ... + 807056.

It is an arithmetic number, because the mean of its divisors is an integer number (32380560).

Almost surely, 2^847664081 is an apocalyptic number.

It is an amenable number.

847664081 is a deficient number, since it is larger than the sum of its proper divisors (188513839).

847664081 is a wasteful number, since it uses less digits than its factorization.

847664081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325.

The product of its (nonzero) digits is 258048, while the sum is 44.

The square root of 847664081 is about 29114.6712329025. The cubic root of 847664081 is about 946.3996991669.

The spelling of 847664081 in words is "eight hundred forty-seven million, six hundred sixty-four thousand, eighty-one".