81851118514 has 32 divisors (see below), whose sum is σ = 142383562560. Its totient is φ = 34897896000.

The previous prime is 81851118511. The next prime is 81851118539. The reversal of 81851118514 is 41581115818.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81851118511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 927169 + ... + 1011604.

It is an arithmetic number, because the mean of its divisors is an integer number (4449486330).

Almost surely, 2^81851118514 is an apocalyptic number.

81851118514 is a deficient number, since it is larger than the sum of its proper divisors (60532444046).

81851118514 is a wasteful number, since it uses less digits than its factorization.

81851118514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1938906.

The product of its digits is 51200, while the sum is 43.

The spelling of 81851118514 in words is "eighty-one billion, eight hundred fifty-one million, one hundred eighteen thousand, five hundred fourteen".