19380955891 has 4 divisors (see below), whose sum is σ = 21142860984. Its totient is φ = 17619050800.

The previous prime is 19380955873. The next prime is 19380955907. The reversal of 19380955891 is 19855908391.

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

It is a cyclic number.

It is not a de Polignac number, because 19380955891 - 2¹¹ = 19380953843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19380955291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880952530 + ... + 880952551.

It is an arithmetic number, because the mean of its divisors is an integer number (5285715246).

Almost surely, 2^19380955891 is an apocalyptic number.

19380955891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19380955891 is a deficient number, since it is larger than the sum of its proper divisors (1761905093).

19380955891 is a wasteful number, since it uses less digits than its factorization.

19380955891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1761905092.

The product of its (nonzero) digits is 3499200, while the sum is 58.

The spelling of 19380955891 in words is "nineteen billion, three hundred eighty million, nine hundred fifty-five thousand, eight hundred ninety-one".