84639861 has 12 divisors (see below), whose sum is σ = 122340192. Its totient is φ = 56388456.

The previous prime is 84639857. The next prime is 84639883. The reversal of 84639861 is 16893648.

84639861 is a `hidden beast` number, since 8 + 4 + 639 + 8 + 6 + 1 = 666.

It is not a de Polignac number, because 84639861 - 2² = 84639857 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84639811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19120 + ... + 23126.

It is an arithmetic number, because the mean of its divisors is an integer number (10195016).

Almost surely, 2^84639861 is an apocalyptic number.

It is an amenable number.

84639861 is a deficient number, since it is larger than the sum of its proper divisors (37700331).

84639861 is a wasteful number, since it uses less digits than its factorization.

84639861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6360 (or 6357 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 84639861 is about 9199.9924456491. The cubic root of 84639861 is about 439.0611195804.

The spelling of 84639861 in words is "eighty-four million, six hundred thirty-nine thousand, eight hundred sixty-one".