19805827967 has 4 divisors (see below), whose sum is σ = 19809799680. Its totient is φ = 19801856256.

The previous prime is 19805827949. The next prime is 19805827973. The reversal of 19805827967 is 76972850891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76972850891 = 76631 ⋅1004461.

It is a cyclic number.

It is not a de Polignac number, because 19805827967 - 2¹⁴ = 19805811583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19805827567) 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, 1978367 + ... + 1988352.

It is an arithmetic number, because the mean of its divisors is an integer number (4952449920).

Almost surely, 2^19805827967 is an apocalyptic number.

19805827967 is a deficient number, since it is larger than the sum of its proper divisors (3971713).

19805827967 is an equidigital number, since it uses as much as digits as its factorization.

19805827967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3971712.

The product of its (nonzero) digits is 15240960, while the sum is 62.

The spelling of 19805827967 in words is "nineteen billion, eight hundred five million, eight hundred twenty-seven thousand, nine hundred sixty-seven".