81634190 has 32 divisors (see below), whose sum is σ = 161499744. Its totient is φ = 29463040.

The previous prime is 81634181. The next prime is 81634213. The reversal of 81634190 is 9143618.

It is a happy number.

It is a super-2 number, since 2×81634190² = 13328281953912200, which contains 22 as substring.

It is a congruent 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, 12362 + ... + 17778.

It is an arithmetic number, because the mean of its divisors is an integer number (5046867).

Almost surely, 2^81634190 is an apocalyptic number.

81634190 is a deficient number, since it is larger than the sum of its proper divisors (79865554).

81634190 is a wasteful number, since it uses less digits than its factorization.

81634190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5572.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 81634190 is about 9035.1640826274. The cubic root of 81634190 is about 433.8011469832.

The spelling of 81634190 in words is "eighty-one million, six hundred thirty-four thousand, one hundred ninety".