101855987 has 4 divisors (see below), whose sum is σ = 105141696. Its totient is φ = 98570280.

The previous prime is 101855977. The next prime is 101855989. The reversal of 101855987 is 789558101.

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: 789558101 = 11491 ⋅68711.

It is a cyclic number.

It is not a de Polignac number, because 101855987 - 2⁸ = 101855731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101855989) 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, 1642808 + ... + 1642869.

It is an arithmetic number, because the mean of its divisors is an integer number (26285424).

Almost surely, 2^101855987 is an apocalyptic number.

101855987 is a deficient number, since it is larger than the sum of its proper divisors (3285709).

101855987 is an equidigital number, since it uses as much as digits as its factorization.

101855987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3285708.

The product of its (nonzero) digits is 100800, while the sum is 44.

The square root of 101855987 is about 10092.3727140846. The cubic root of 101855987 is about 467.0128751225.

The spelling of 101855987 in words is "one hundred one million, eight hundred fifty-five thousand, nine hundred eighty-seven".