19901889 has 40 divisors (see below), whose sum is σ = 34508320. Its totient is φ = 11335464.

The previous prime is 19901867. The next prime is 19901897. The reversal of 19901889 is 98810991.

It is not a de Polignac number, because 19901889 - 2⁵ = 19901857 is a prime.

It is a nialpdrome in base 7.

It is a zygodrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (19901839) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 64674 + ... + 64980.

It is an arithmetic number, because the mean of its divisors is an integer number (862708).

Almost surely, 2^19901889 is an apocalyptic number.

It is an amenable number.

19901889 is a deficient number, since it is larger than the sum of its proper divisors (14606431).

19901889 is an frugal number, since it uses more digits than its factorization.

19901889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 45.

The square root of 19901889 is about 4461.1533262151. The cubic root of 19901889 is about 270.9971768427.

The spelling of 19901889 in words is "nineteen million, nine hundred one thousand, eight hundred eighty-nine".