81812902 has 8 divisors (see below), whose sum is σ = 123270336. Its totient is φ = 40722792.

The previous prime is 81812897. The next prime is 81812921. The reversal of 81812902 is 20921818.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 91273 + ... + 92164.

It is an arithmetic number, because the mean of its divisors is an integer number (15408792).

Almost surely, 2^81812902 is an apocalyptic number.

81812902 is a deficient number, since it is larger than the sum of its proper divisors (41457434).

81812902 is a wasteful number, since it uses less digits than its factorization.

81812902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183662.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 81812902 is about 9045.0484796932. The cubic root of 81812902 is about 434.1174726423.

The spelling of 81812902 in words is "eighty-one million, eight hundred twelve thousand, nine hundred two".