19801321771 has 16 divisors (see below), whose sum is σ = 25538653440. Its totient is φ = 14897544480.

The previous prime is 19801321769. The next prime is 19801321777. The reversal of 19801321771 is 17712310891.

It is not a de Polignac number, because 19801321771 - 2¹ = 19801321769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19801321777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4431561 + ... + 4436026.

It is an arithmetic number, because the mean of its divisors is an integer number (1596165840).

Almost surely, 2^19801321771 is an apocalyptic number.

19801321771 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19801321771 is a deficient number, since it is larger than the sum of its proper divisors (5737331669).

19801321771 is a wasteful number, since it uses less digits than its factorization.

19801321771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8867634.

The product of its (nonzero) digits is 21168, while the sum is 40.

The spelling of 19801321771 in words is "nineteen billion, eight hundred one million, three hundred twenty-one thousand, seven hundred seventy-one".