19891812090 has 16 divisors (see below), whose sum is σ = 47740349088. Its totient is φ = 5304483216.

The previous prime is 19891812089. The next prime is 19891812103. The reversal of 19891812090 is 9021819891.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 331530172 + ... + 331530231.

It is an arithmetic number, because the mean of its divisors is an integer number (2983771818).

Almost surely, 2^19891812090 is an apocalyptic number.

19891812090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19891812090 is an abundant number, since it is smaller than the sum of its proper divisors (27848536998).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19891812090 is a wasteful number, since it uses less digits than its factorization.

19891812090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663060413.

The product of its (nonzero) digits is 93312, while the sum is 48.

The spelling of 19891812090 in words is "nineteen billion, eight hundred ninety-one million, eight hundred twelve thousand, ninety".