87186516481 has 4 divisors (see below), whose sum is σ = 87268076500. Its totient is φ = 87104956464.

The previous prime is 87186516451. The next prime is 87186516623. The reversal of 87186516481 is 18461568178.

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 14079009025 + 73107507456 = 118655^2 + 270384^2 .

It is a cyclic number.

It is not a de Polignac number, because 87186516481 - 2⁵ = 87186516449 is a prime.

It is a super-2 number, since 2×87186516481² (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 (87186516451) 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, 40778406 + ... + 40780543.

It is an arithmetic number, because the mean of its divisors is an integer number (21817019125).

Almost surely, 2^87186516481 is an apocalyptic number.

It is an amenable number.

87186516481 is a deficient number, since it is larger than the sum of its proper divisors (81560019).

87186516481 is a wasteful number, since it uses less digits than its factorization.

87186516481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81560018.

The product of its digits is 2580480, while the sum is 55.

The spelling of 87186516481 in words is "eighty-seven billion, one hundred eighty-six million, five hundred sixteen thousand, four hundred eighty-one".