81910458 has 48 divisors (see below), whose sum is σ = 206980800. Its totient is φ = 23401224.

The previous prime is 81910447. The next prime is 81910487. The reversal of 81910458 is 85401918.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 460 + ... + 12807.

It is an arithmetic number, because the mean of its divisors is an integer number (4312100).

Almost surely, 2^81910458 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81910458, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103490400).

81910458 is an abundant number, since it is smaller than the sum of its proper divisors (125070342).

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

81910458 is a wasteful number, since it uses less digits than its factorization.

81910458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13296 (or 13279 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 81910458 is about 9050.4396578288. The cubic root of 81910458 is about 434.2899553879.

The spelling of 81910458 in words is "eighty-one million, nine hundred ten thousand, four hundred fifty-eight".