81858755 has 32 divisors (see below), whose sum is σ = 113412096. Its totient is φ = 56160000.

The previous prime is 81858743. The next prime is 81858781. The reversal of 81858755 is 55785818.

It is not a de Polignac number, because 81858755 - 2⁶ = 81858691 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69320 + ... + 70490.

It is an arithmetic number, because the mean of its divisors is an integer number (3544128).

Almost surely, 2^81858755 is an apocalyptic number.

81858755 is a deficient number, since it is larger than the sum of its proper divisors (31553341).

81858755 is a wasteful number, since it uses less digits than its factorization.

81858755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1259.

The product of its digits is 448000, while the sum is 47.

The square root of 81858755 is about 9047.5828263686. The cubic root of 81858755 is about 434.1985595710.

The spelling of 81858755 in words is "eighty-one million, eight hundred fifty-eight thousand, seven hundred fifty-five".