86172522721 has 4 divisors (see below), whose sum is σ = 86176226052. Its totient is φ = 86168819392.

The previous prime is 86172522719. The next prime is 86172522767. The reversal of 86172522721 is 12722527168.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 63383601121 + 22788921600 = 251761^2 + 150960^2 .

It is a cyclic number.

It is not a de Polignac number, because 86172522721 - 2¹ = 86172522719 is a prime.

It is a super-2 number, since 2×86172522721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (86172522221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1816540 + ... + 1863373.

It is an arithmetic number, because the mean of its divisors is an integer number (21544056513).

Almost surely, 2^86172522721 is an apocalyptic number.

It is an amenable number.

86172522721 is a deficient number, since it is larger than the sum of its proper divisors (3703331).

86172522721 is a wasteful number, since it uses less digits than its factorization.

86172522721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3703330.

The product of its digits is 188160, while the sum is 43.

The spelling of 86172522721 in words is "eighty-six billion, one hundred seventy-two million, five hundred twenty-two thousand, seven hundred twenty-one".