81766797841 has 16 divisors (see below), whose sum is σ = 87162660864. Its totient is φ = 76525306704.

The previous prime is 81766797823. The next prime is 81766797857. The reversal of 81766797841 is 14879766718.

It is a happy number.

It is not a de Polignac number, because 81766797841 - 2⁷ = 81766797713 is a prime.

It is a super-3 number, since 3×81766797841³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81766797821) 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, 4577770 + ... + 4595596.

It is an arithmetic number, because the mean of its divisors is an integer number (5447666304).

Almost surely, 2^81766797841 is an apocalyptic number.

It is an amenable number.

81766797841 is a deficient number, since it is larger than the sum of its proper divisors (5395863023).

81766797841 is a wasteful number, since it uses less digits than its factorization.

81766797841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22140.

The product of its digits is 28449792, while the sum is 64.

The spelling of 81766797841 in words is "eighty-one billion, seven hundred sixty-six million, seven hundred ninety-seven thousand, eight hundred forty-one".