19821432161 has 4 divisors (see below), whose sum is σ = 19828923072. Its totient is φ = 19813941252.

The previous prime is 19821432119. The next prime is 19821432203. The reversal of 19821432161 is 16123412891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16123412891 = 8933 ⋅1804927.

It is an interprime number because it is at equal distance from previous prime (19821432119) and next prime (19821432203).

It is a cyclic number.

It is not a de Polignac number, because 19821432161 - 2²² = 19817237857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19821432661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3741485 + ... + 3746778.

It is an arithmetic number, because the mean of its divisors is an integer number (4957230768).

Almost surely, 2^19821432161 is an apocalyptic number.

It is an amenable number.

19821432161 is a deficient number, since it is larger than the sum of its proper divisors (7490911).

19821432161 is an equidigital number, since it uses as much as digits as its factorization.

19821432161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7490910.

The product of its digits is 20736, while the sum is 38.

The spelling of 19821432161 in words is "nineteen billion, eight hundred twenty-one million, four hundred thirty-two thousand, one hundred sixty-one".