1900100091 has 4 divisors (see below), whose sum is σ = 2533466792. Its totient is φ = 1266733392.

The previous prime is 1900100087. The next prime is 1900100107. The reversal of 1900100091 is 1900010091.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1900100091 - 2² = 1900100087 is a prime.

It is a super-2 number, since 2×1900100091² = 7220760711636416562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1900180091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 316683346 + ... + 316683351.

It is an arithmetic number, because the mean of its divisors is an integer number (633366698).

Almost surely, 2^1900100091 is an apocalyptic number.

1900100091 is a deficient number, since it is larger than the sum of its proper divisors (633366701).

1900100091 is an equidigital number, since it uses as much as digits as its factorization.

1900100091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633366700.

The product of its (nonzero) digits is 81, while the sum is 21.

The square root of 1900100091 is about 43590.1375427975. The cubic root of 1900100091 is about 1238.5840781855.

Subtracting from 1900100091 its reverse (1900010091), we obtain a square (90000 = 300²).

The spelling of 1900100091 in words is "one billion, nine hundred million, one hundred thousand, ninety-one".