87918638842 has 4 divisors (see below), whose sum is σ = 131877958266. Its totient is φ = 43959319420.

The previous prime is 87918638749. The next prime is 87918638849. The reversal of 87918638842 is 24883681978.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24883681978 = 2 ⋅12441840989.

It can be written as a sum of positive squares in only one way, i.e., 78238243521 + 9680395321 = 279711^2 + 98389^2 .

It is a super-2 number, since 2×87918638842² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (87918638849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21979659709 + ... + 21979659712.

Almost surely, 2^87918638842 is an apocalyptic number.

87918638842 is a deficient number, since it is larger than the sum of its proper divisors (43959319424).

87918638842 is a wasteful number, since it uses less digits than its factorization.

87918638842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43959319423.

The product of its digits is 37158912, while the sum is 64.

The spelling of 87918638842 in words is "eighty-seven billion, nine hundred eighteen million, six hundred thirty-eight thousand, eight hundred forty-two".