81968902 has 4 divisors (see below), whose sum is σ = 122953356. Its totient is φ = 40984450.

The previous prime is 81968897. The next prime is 81968903. The reversal of 81968902 is 20986918.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81968903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20492224 + ... + 20492227.

It is an arithmetic number, because the mean of its divisors is an integer number (30738339).

Almost surely, 2^81968902 is an apocalyptic number.

81968902 is a deficient number, since it is larger than the sum of its proper divisors (40984454).

81968902 is a wasteful number, since it uses less digits than its factorization.

81968902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40984453.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 81968902 is about 9053.6678755077. The cubic root of 81968902 is about 434.3932210289.

The spelling of 81968902 in words is "eighty-one million, nine hundred sixty-eight thousand, nine hundred two".