81213535886 has 16 divisors (see below), whose sum is σ = 140145216000. Its totient is φ = 34575298200.

The previous prime is 81213535867. The next prime is 81213535927. The reversal of 81213535886 is 68853531218.

It is a happy number.

It is a super-2 number, since 2×81213535886² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

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, 19206386 + ... + 19210613.

It is an arithmetic number, because the mean of its divisors is an integer number (8759076000).

Almost surely, 2^81213535886 is an apocalyptic number.

81213535886 is a deficient number, since it is larger than the sum of its proper divisors (58931680114).

81213535886 is a wasteful number, since it uses less digits than its factorization.

81213535886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38417159.

The product of its digits is 1382400, while the sum is 50.

The spelling of 81213535886 in words is "eighty-one billion, two hundred thirteen million, five hundred thirty-five thousand, eight hundred eighty-six".