101861 has 4 divisors (see below), whose sum is σ = 104652. Its totient is φ = 99072.

The previous prime is 101839. The next prime is 101863. The reversal of 101861 is 168101.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 168101 = 97 ⋅1733.

It can be written as a sum of positive squares in 2 ways, for example, as 93025 + 8836 = 305^2 + 94^2 .

It is a cyclic number.

It is not a de Polignac number, because 101861 - 2⁶ = 101797 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 (101863) 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, 1340 + ... + 1413.

It is an arithmetic number, because the mean of its divisors is an integer number (26163).

2¹⁰¹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

101861 is a deficient number, since it is larger than the sum of its proper divisors (2791).

101861 is an equidigital number, since it uses as much as digits as its factorization.

101861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2790.

The product of its (nonzero) digits is 48, while the sum is 17.

The square root of 101861 is about 319.1567013240. The cubic root of 101861 is about 46.7020536584.

Adding to 101861 its reverse (168101), we get a palindrome (269962).

The spelling of 101861 in words is "one hundred one thousand, eight hundred sixty-one".