81609893192 has 24 divisors (see below), whose sum is σ = 158477012850. Its totient is φ = 39397876224.

The previous prime is 81609893177. The next prime is 81609893207. The reversal of 81609893192 is 29139890618.

It is an interprime number because it is at equal distance from previous prime (81609893177) and next prime (81609893207).

It can be written as a sum of positive squares in 3 ways, for example, as 62937763876 + 18672129316 = 250874^2 + 136646^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6058217 + ... + 6071672.

Almost surely, 2^81609893192 is an apocalyptic number.

It is an amenable number.

81609893192 is a deficient number, since it is larger than the sum of its proper divisors (76867119658).

81609893192 is a wasteful number, since it uses less digits than its factorization.

81609893192 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12129953 (or 12129920 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 56.

The spelling of 81609893192 in words is "eighty-one billion, six hundred nine million, eight hundred ninety-three thousand, one hundred ninety-two".