81840922 has 4 divisors (see below), whose sum is σ = 122761386. Its totient is φ = 40920460.

The previous prime is 81840827. The next prime is 81840947. The reversal of 81840922 is 22904818.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 81558961 + 281961 = 9031^2 + 531^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20460229 + ... + 20460232.

Almost surely, 2^81840922 is an apocalyptic number.

81840922 is a deficient number, since it is larger than the sum of its proper divisors (40920464).

81840922 is a wasteful number, since it uses less digits than its factorization.

81840922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40920463.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 81840922 is about 9046.5972608490. The cubic root of 81840922 is about 434.1670271048.

The spelling of 81840922 in words is "eighty-one million, eight hundred forty thousand, nine hundred twenty-two".