81171216157 has 8 divisors (see below), whose sum is σ = 85948584192. Its totient is φ = 76394136000.

The previous prime is 81171216103. The next prime is 81171216209. The reversal of 81171216157 is 75161217118.

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 81171216157 - 2¹¹ = 81171214109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81171217157) 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, 835782 + ... + 927832.

It is an arithmetic number, because the mean of its divisors is an integer number (10743573024).

Almost surely, 2^81171216157 is an apocalyptic number.

It is an amenable number.

81171216157 is a deficient number, since it is larger than the sum of its proper divisors (4777368035).

81171216157 is a wasteful number, since it uses less digits than its factorization.

81171216157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143939.

The product of its digits is 23520, while the sum is 40.

The spelling of 81171216157 in words is "eighty-one billion, one hundred seventy-one million, two hundred sixteen thousand, one hundred fifty-seven".