847649138 has 54 divisors (see below), whose sum is σ = 1580317191. Its totient is φ = 339932544.

The previous prime is 847649137. The next prime is 847649161. The reversal of 847649138 is 831946748.

It can be written as a sum of positive squares in 5 ways, for example, as 847566769 + 82369 = 29113^2 + 287^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=20587.

It is a super-2 number, since 2×847649138² = 1437018122304286088, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (847649137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4899620 + ... + 4899792.

Almost surely, 2^847649138 is an apocalyptic number.

847649138 is a deficient number, since it is larger than the sum of its proper divisors (732668053).

847649138 is a wasteful number, since it uses less digits than its factorization.

847649138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 199 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 50.

The square root of 847649138 is about 29114.4146085749. The cubic root of 847649138 is about 946.3941379491.

Multiplying 847649138 by its sum of digits (50), we get a square (42382456900 = 205870²).

The spelling of 847649138 in words is "eight hundred forty-seven million, six hundred forty-nine thousand, one hundred thirty-eight".