81698111221 has 8 divisors (see below), whose sum is σ = 84717007200. Its totient is φ = 78692663280.

The previous prime is 81698111213. The next prime is 81698111227. The reversal of 81698111221 is 12211189618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81698111221 - 2³ = 81698111213 is a prime.

It is a super-2 number, since 2×81698111221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81698111227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3349635 + ... + 3373936.

It is an arithmetic number, because the mean of its divisors is an integer number (10589625900).

Almost surely, 2^81698111221 is an apocalyptic number.

It is an amenable number.

81698111221 is a deficient number, since it is larger than the sum of its proper divisors (3018895979).

81698111221 is a wasteful number, since it uses less digits than its factorization.

81698111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6724019.

The product of its digits is 13824, while the sum is 40.

The spelling of 81698111221 in words is "eighty-one billion, six hundred ninety-eight million, one hundred eleven thousand, two hundred twenty-one".