81851754 has 32 divisors (see below), whose sum is σ = 166256640. Its totient is φ = 26862192.

The previous prime is 81851743. The next prime is 81851789. The reversal of 81851754 is 45715818.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123877 + ... + 124535.

It is an arithmetic number, because the mean of its divisors is an integer number (5195520).

Almost surely, 2^81851754 is an apocalyptic number.

81851754 is an abundant number, since it is smaller than the sum of its proper divisors (84404886).

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

81851754 is a wasteful number, since it uses less digits than its factorization.

81851754 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 954.

The product of its digits is 44800, while the sum is 39.

The square root of 81851754 is about 9047.1959191785. The cubic root of 81851754 is about 434.1861808878.

The spelling of 81851754 in words is "eighty-one million, eight hundred fifty-one thousand, seven hundred fifty-four".