819668643 has 8 divisors (see below), whose sum is σ = 1093693008. Its totient is φ = 546045024.

The previous prime is 819668639. The next prime is 819668653. The reversal of 819668643 is 346866918.

819668643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 819668643 - 2² = 819668639 is a prime.

It is a super-2 number, since 2×819668643² = 1343713368634922898, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (819668653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95380 + ... + 103617.

It is an arithmetic number, because the mean of its divisors is an integer number (136711626).

Almost surely, 2^819668643 is an apocalyptic number.

819668643 is a deficient number, since it is larger than the sum of its proper divisors (274024365).

819668643 is a wasteful number, since it uses less digits than its factorization.

819668643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200373.

The product of its digits is 1492992, while the sum is 51.

The square root of 819668643 is about 28629.8557977507. The cubic root of 819668643 is about 935.8640693557.

It can be divided in two parts, 81966 and 8643, that added together give a palindrome (90609).

The spelling of 819668643 in words is "eight hundred nineteen million, six hundred sixty-eight thousand, six hundred forty-three".