101981109 has 4 divisors (see below), whose sum is σ = 135974816. Its totient is φ = 67987404.

The previous prime is 101981107. The next prime is 101981137. The reversal of 101981109 is 901189101.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 101981109 - 2¹ = 101981107 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 (101981101) 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, 16996849 + ... + 16996854.

It is an arithmetic number, because the mean of its divisors is an integer number (33993704).

Almost surely, 2^101981109 is an apocalyptic number.

It is an amenable number.

101981109 is a deficient number, since it is larger than the sum of its proper divisors (33993707).

101981109 is an equidigital number, since it uses as much as digits as its factorization.

101981109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33993706.

The product of its (nonzero) digits is 648, while the sum is 30.

The square root of 101981109 is about 10098.5696511932. The cubic root of 101981109 is about 467.2040262958.

It can be divided in two parts, 1019 and 81109, that added together give a palindrome (82128).

The spelling of 101981109 in words is "one hundred one million, nine hundred eighty-one thousand, one hundred nine".