1821811500197 has 16 divisors (see below), whose sum is σ = 1963655484672. Its totient is φ = 1680211589760.

The previous prime is 1821811500191. The next prime is 1821811500253. The reversal of 1821811500197 is 7910051181281.

It is a cyclic number.

It is not a de Polignac number, because 1821811500197 - 2¹² = 1821811496101 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 (1821811500191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113450993 + ... + 113467049.

It is an arithmetic number, because the mean of its divisors is an integer number (122728467792).

Almost surely, 2^{1821811500197} is an apocalyptic number.

It is an amenable number.

1821811500197 is a deficient number, since it is larger than the sum of its proper divisors (141843984475).

1821811500197 is a wasteful number, since it uses less digits than its factorization.

1821811500197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23108.

The product of its (nonzero) digits is 40320, while the sum is 44.

The spelling of 1821811500197 in words is "one trillion, eight hundred twenty-one billion, eight hundred eleven million, five hundred thousand, one hundred ninety-seven".