81489637786 has 16 divisors (see below), whose sum is σ = 122755726080. Its totient is φ = 40571254800.

The previous prime is 81489637769. The next prime is 81489637811. The reversal of 81489637786 is 68773698418.

It is a happy number.

It is a super-2 number, since 2×81489637786² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 816511 + ... + 910861.

It is an arithmetic number, because the mean of its divisors is an integer number (7672232880).

Almost surely, 2^81489637786 is an apocalyptic number.

81489637786 is a deficient number, since it is larger than the sum of its proper divisors (41266088294).

81489637786 is a wasteful number, since it uses less digits than its factorization.

81489637786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96189.

The product of its digits is 97542144, while the sum is 67.

The spelling of 81489637786 in words is "eighty-one billion, four hundred eighty-nine million, six hundred thirty-seven thousand, seven hundred eighty-six".