101811993 has 16 divisors (see below), whose sum is σ = 140667840. Its totient is φ = 65459264.

The previous prime is 101811991. The next prime is 101812001. The reversal of 101811993 is 399118101.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 101811993 - 2¹ = 101811991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (101811991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3955 + ... + 14807.

It is an arithmetic number, because the mean of its divisors is an integer number (8791740).

Almost surely, 2^101811993 is an apocalyptic number.

It is an amenable number.

101811993 is a deficient number, since it is larger than the sum of its proper divisors (38855847).

101811993 is a wasteful number, since it uses less digits than its factorization.

101811993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10968.

The product of its (nonzero) digits is 1944, while the sum is 33.

The square root of 101811993 is about 10090.1929119319. The cubic root of 101811993 is about 466.9456274859.

The spelling of 101811993 in words is "one hundred one million, eight hundred eleven thousand, nine hundred ninety-three".