81810358 has 32 divisors (see below), whose sum is σ = 149174784. Its totient is φ = 32848512.

The previous prime is 81810349. The next prime is 81810373. The reversal of 81810358 is 85301818.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 61941 + ... + 63247.

It is an arithmetic number, because the mean of its divisors is an integer number (4661712).

Almost surely, 2^81810358 is an apocalyptic number.

81810358 is a deficient number, since it is larger than the sum of its proper divisors (67364426).

81810358 is a wasteful number, since it uses less digits than its factorization.

81810358 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1596.

The product of its (nonzero) digits is 7680, while the sum is 34.

The square root of 81810358 is about 9044.9078491713. The cubic root of 81810358 is about 434.1129729188.

The spelling of 81810358 in words is "eighty-one million, eight hundred ten thousand, three hundred fifty-eight".