101986 has 4 divisors (see below), whose sum is σ = 152982. Its totient is φ = 50992.

The previous prime is 101977. The next prime is 101987. The reversal of 101986 is 689101.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689101 = 7 ⋅98443.

It can be written as a sum of positive squares in only one way, i.e., 101761 + 225 = 319^2 + 15^2 .

It is a super-2 number, since 2×101986² = 20802288392, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 101986.

It is not an unprimeable number, because it can be changed into a prime (101987) by changing a digit.

101986 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25495 + ... + 25498.

2¹⁰¹⁹⁸⁶ is an apocalyptic number.

101986 is a deficient number, since it is larger than the sum of its proper divisors (50996).

101986 is an equidigital number, since it uses as much as digits as its factorization.

101986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50995.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 101986 is about 319.3524698511. The cubic root of 101986 is about 46.7211495190.

The spelling of 101986 in words is "one hundred one thousand, nine hundred eighty-six".