81398902 has 16 divisors (see below), whose sum is σ = 131643792. Its totient is φ = 37524960.

The previous prime is 81398893. The next prime is 81398923. The reversal of 81398902 is 20989318.

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 7 ways as a sum of consecutive naturals, for example, 34773 + ... + 37039.

It is an arithmetic number, because the mean of its divisors is an integer number (8227737).

Almost surely, 2^81398902 is an apocalyptic number.

81398902 is a deficient number, since it is larger than the sum of its proper divisors (50244890).

81398902 is a wasteful number, since it uses less digits than its factorization.

81398902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3663.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 81398902 is about 9022.1340047685. The cubic root of 81398902 is about 433.3839752780.

The spelling of 81398902 in words is "eighty-one million, three hundred ninety-eight thousand, nine hundred two".