1821943497 has 32 divisors (see below), whose sum is σ = 2854494720. Its totient is φ = 1021749120.

The previous prime is 1821943477. The next prime is 1821943511. The reversal of 1821943497 is 7943491281.

It is not a de Polignac number, because 1821943497 - 2¹¹ = 1821941449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1821943477) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6828 + ... + 60749.

It is an arithmetic number, because the mean of its divisors is an integer number (89202960).

Almost surely, 2^1821943497 is an apocalyptic number.

It is an amenable number.

1821943497 is a deficient number, since it is larger than the sum of its proper divisors (1032551223).

1821943497 is a wasteful number, since it uses less digits than its factorization.

1821943497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67653.

The product of its digits is 435456, while the sum is 48.

The square root of 1821943497 is about 42684.2300738809. The cubic root of 1821943497 is about 1221.3635871117.

It can be divided in two parts, 18219 and 43497, that added together give a palindrome (61716).

The spelling of 1821943497 in words is "one billion, eight hundred twenty-one million, nine hundred forty-three thousand, four hundred ninety-seven".