78531861 has 8 divisors (see below), whose sum is σ = 105971040. Its totient is φ = 51723632.

The previous prime is 78531841. The next prime is 78531899. The reversal of 78531861 is 16813587.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78531861 - 2⁵ = 78531829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78531841) 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 7 ways as a sum of consecutive naturals, for example, 157446 + ... + 157943.

It is an arithmetic number, because the mean of its divisors is an integer number (13246380).

Almost surely, 2^78531861 is an apocalyptic number.

It is an amenable number.

78531861 is a deficient number, since it is larger than the sum of its proper divisors (27439179).

78531861 is a wasteful number, since it uses less digits than its factorization.

78531861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315475.

The product of its digits is 40320, while the sum is 39.

The square root of 78531861 is about 8861.8204111796. The cubic root of 78531861 is about 428.2348061604.

The spelling of 78531861 in words is "seventy-eight million, five hundred thirty-one thousand, eight hundred sixty-one".