86993781 has 16 divisors (see below), whose sum is σ = 136839168. Its totient is φ = 48106800.

The previous prime is 86993749. The next prime is 86993783. The reversal of 86993781 is 18739968.

It is not a de Polignac number, because 86993781 - 2⁵ = 86993749 is a prime.

It is a super-2 number, since 2×86993781² = 15135835865351922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86993783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66165 + ... + 67466.

It is an arithmetic number, because the mean of its divisors is an integer number (8552448).

Almost surely, 2^86993781 is an apocalyptic number.

It is an amenable number.

86993781 is a deficient number, since it is larger than the sum of its proper divisors (49845387).

86993781 is a wasteful number, since it uses less digits than its factorization.

86993781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133672.

The product of its digits is 653184, while the sum is 51.

The square root of 86993781 is about 9327.0456737383. The cubic root of 86993781 is about 443.0942038009.

The spelling of 86993781 in words is "eighty-six million, nine hundred ninety-three thousand, seven hundred eighty-one".