819491973 has 8 divisors (see below), whose sum is σ = 1092792288. Its totient is φ = 546259824.

The previous prime is 819491963. The next prime is 819492031. The reversal of 819491973 is 379194918.

It is a happy number.

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

It is not a de Polignac number, because 819491973 - 2⁹ = 819491461 is a prime.

It is a super-2 number, since 2×819491973² = 1343134187622865458, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (819491923) 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 7 ways as a sum of consecutive naturals, for example, 28086 + ... + 49272.

It is an arithmetic number, because the mean of its divisors is an integer number (136599036).

Almost surely, 2^819491973 is an apocalyptic number.

It is an amenable number.

819491973 is a deficient number, since it is larger than the sum of its proper divisors (273300315).

819491973 is a wasteful number, since it uses less digits than its factorization.

819491973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34083.

The product of its digits is 489888, while the sum is 51.

The square root of 819491973 is about 28626.7702160059. The cubic root of 819491973 is about 935.7968263354.

The spelling of 819491973 in words is "eight hundred nineteen million, four hundred ninety-one thousand, nine hundred seventy-three".