81162171869 has 8 divisors (see below), whose sum is σ = 81220400352. Its totient is φ = 81103970320.

The previous prime is 81162171773. The next prime is 81162171899. The reversal of 81162171869 is 96817126118.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81162171869 is a prime.

It is a super-2 number, since 2×81162171869² (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 (81162171899) 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, 13234934 + ... + 13241064.

It is an arithmetic number, because the mean of its divisors is an integer number (10152550044).

Almost surely, 2^81162171869 is an apocalyptic number.

It is an amenable number.

81162171869 is a deficient number, since it is larger than the sum of its proper divisors (58228483).

81162171869 is a wasteful number, since it uses less digits than its factorization.

81162171869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13467.

The product of its digits is 290304, while the sum is 50.

The spelling of 81162171869 in words is "eighty-one billion, one hundred sixty-two million, one hundred seventy-one thousand, eight hundred sixty-nine".