100001199981 has 4 divisors (see below), whose sum is σ = 133334933312. Its totient is φ = 66667466652.

The previous prime is 100001199979. The next prime is 100001200031. The reversal of 100001199981 is 189991100001.

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 100001199981 - 2¹ = 100001199979 is a prime.

It is a super-2 number, since 2×100001199981² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100001199901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16666866661 + ... + 16666866666.

It is an arithmetic number, because the mean of its divisors is an integer number (33333733328).

Almost surely, 2^100001199981 is an apocalyptic number.

It is an amenable number.

100001199981 is a deficient number, since it is larger than the sum of its proper divisors (33333733331).

100001199981 is an equidigital number, since it uses as much as digits as its factorization.

100001199981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33333733330.

The product of its (nonzero) digits is 5832, while the sum is 39.

Adding to 100001199981 its reverse (189991100001), we get a palindrome (289992299982).

The spelling of 100001199981 in words is "one hundred billion, one million, one hundred ninety-nine thousand, nine hundred eighty-one".