1821121488916 has 12 divisors (see below), whose sum is σ = 3195155314260. Its totient is φ = 908219970560.

The previous prime is 1821121488881. The next prime is 1821121488917. The reversal of 1821121488916 is 6198841211281.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1173733892100 + 647387596816 = 1083390^2 + 804604^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821121488917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 585191725 + ... + 585194836.

It is an arithmetic number, because the mean of its divisors is an integer number (266262942855).

Almost surely, 2^{1821121488916} is an apocalyptic number.

It is an amenable number.

1821121488916 is a deficient number, since it is larger than the sum of its proper divisors (1374033825344).

1821121488916 is a wasteful number, since it uses less digits than its factorization.

1821121488916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170386954 (or 1170386952 counting only the distinct ones).

The product of its digits is 442368, while the sum is 52.

The spelling of 1821121488916 in words is "one trillion, eight hundred twenty-one billion, one hundred twenty-one million, four hundred eighty-eight thousand, nine hundred sixteen".