1919901091 has 2 divisors, whose sum is σ = 1919901092. Its totient is φ = 1919901090.

The previous prime is 1919901079. The next prime is 1919901119. The reversal of 1919901091 is 1901099191.

It is a weak prime.

It is an emirp because it is prime and its reverse (1901099191) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1601066161 and 1616601061.

It is a cyclic number.

It is not a de Polignac number, because 1919901091 - 2⁵ = 1919901059 is a prime.

It is not a weakly prime, because it can be changed into another prime (1919901031) 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 as a sum of consecutive naturals, namely, 959950545 + 959950546.

It is an arithmetic number, because the mean of its divisors is an integer number (959950546).

Almost surely, 2^1919901091 is an apocalyptic number.

1919901091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919901091 is an equidigital number, since it uses as much as digits as its factorization.

1919901091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6561, while the sum is 40.

The square root of 1919901091 is about 43816.6759464932. The cubic root of 1919901091 is about 1242.8716594275.

The spelling of 1919901091 in words is "one billion, nine hundred nineteen million, nine hundred one thousand, ninety-one".