81822290 has 32 divisors (see below), whose sum is σ = 161961984. Its totient is φ = 29514240.

The previous prime is 81822271. The next prime is 81822337. The reversal of 81822290 is 9222818.

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, 11042 + ... + 16898.

It is an arithmetic number, because the mean of its divisors is an integer number (5061312).

Almost surely, 2^81822290 is an apocalyptic number.

81822290 is a deficient number, since it is larger than the sum of its proper divisors (80139694).

81822290 is a wasteful number, since it uses less digits than its factorization.

81822290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6002.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 81822290 is about 9045.5674227767. The cubic root of 81822290 is about 434.1340769465.

The spelling of 81822290 in words is "eighty-one million, eight hundred twenty-two thousand, two hundred ninety".