81865374 has 8 divisors (see below), whose sum is σ = 163730760. Its totient is φ = 27288456.

The previous prime is 81865373. The next prime is 81865453. The reversal of 81865374 is 47356818.

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

81865374 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81865373) 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 3 ways as a sum of consecutive naturals, for example, 6822109 + ... + 6822120.

It is an arithmetic number, because the mean of its divisors is an integer number (20466345).

Almost surely, 2^81865374 is an apocalyptic number.

81865374 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81865374 is a wasteful number, since it uses less digits than its factorization.

81865374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13644234.

The product of its digits is 161280, while the sum is 42.

The square root of 81865374 is about 9047.9486072811. The cubic root of 81865374 is about 434.2102621791.

The spelling of 81865374 in words is "eighty-one million, eight hundred sixty-five thousand, three hundred seventy-four".