81210322 has 4 divisors (see below), whose sum is σ = 121815486. Its totient is φ = 40605160.

The previous prime is 81210307. The next prime is 81210323. The reversal of 81210322 is 22301218.

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., 80084601 + 1125721 = 8949^2 + 1061^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81210322.

It is not an unprimeable number, because it can be changed into a prime (81210323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20302579 + ... + 20302582.

Almost surely, 2^81210322 is an apocalyptic number.

81210322 is a deficient number, since it is larger than the sum of its proper divisors (40605164).

81210322 is a wasteful number, since it uses less digits than its factorization.

81210322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40605163.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 81210322 is about 9011.6769804515. The cubic root of 81210322 is about 433.0490373235.

The spelling of 81210322 in words is "eighty-one million, two hundred ten thousand, three hundred twenty-two".