87781818893 has 4 divisors (see below), whose sum is σ = 89922838908. Its totient is φ = 85640798880.

The previous prime is 87781818863. The next prime is 87781818911. The reversal of 87781818893 is 39881818778.

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 1685348809 + 86096470084 = 41053^2 + 293422^2 .

It is a cyclic number.

It is not a de Polignac number, because 87781818893 - 2⁶ = 87781818829 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 (87781818823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1070509946 + ... + 1070510027.

It is an arithmetic number, because the mean of its divisors is an integer number (22480709727).

Almost surely, 2^87781818893 is an apocalyptic number.

It is an amenable number.

87781818893 is a deficient number, since it is larger than the sum of its proper divisors (2141020015).

87781818893 is a wasteful number, since it uses less digits than its factorization.

87781818893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2141020014.

The product of its digits is 43352064, while the sum is 68.

The spelling of 87781818893 in words is "eighty-seven billion, seven hundred eighty-one million, eight hundred eighteen thousand, eight hundred ninety-three".