19890931943 has 4 divisors (see below), whose sum is σ = 19898266368. Its totient is φ = 19883597520.

The previous prime is 19890931939. The next prime is 19890931961. The reversal of 19890931943 is 34913909891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34913909891 = 7 ⋅4987701413.

It is a cyclic number.

It is not a de Polignac number, because 19890931943 - 2² = 19890931939 is a prime.

It is a super-2 number, since 2×19890931943² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19890931903) 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, 3663143 + ... + 3668568.

It is an arithmetic number, because the mean of its divisors is an integer number (4974566592).

Almost surely, 2^19890931943 is an apocalyptic number.

19890931943 is a deficient number, since it is larger than the sum of its proper divisors (7334425).

19890931943 is an equidigital number, since it uses as much as digits as its factorization.

19890931943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7334424.

The product of its (nonzero) digits is 1889568, while the sum is 56.

The spelling of 19890931943 in words is "nineteen billion, eight hundred ninety million, nine hundred thirty-one thousand, nine hundred forty-three".