81156858 has 32 divisors (see below), whose sum is σ = 165749760. Its totient is φ = 26485680.

The previous prime is 81156851. The next prime is 81156871. The reversal of 81156858 is 85865118.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81156851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61441 + ... + 62747.

It is an arithmetic number, because the mean of its divisors is an integer number (5179680).

Almost surely, 2^81156858 is an apocalyptic number.

81156858 is an abundant number, since it is smaller than the sum of its proper divisors (84592902).

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

81156858 is a wasteful number, since it uses less digits than its factorization.

81156858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1522.

The product of its digits is 76800, while the sum is 42.

The square root of 81156858 is about 9008.7101185464. The cubic root of 81156858 is about 432.9539852999.

The spelling of 81156858 in words is "eighty-one million, one hundred fifty-six thousand, eight hundred fifty-eight".