1920009191821 has 16 divisors (see below), whose sum is σ = 2316219494400. Its totient is φ = 1554762258288.

The previous prime is 1920009191813. The next prime is 1920009191879. The reversal of 1920009191821 is 1281919000291.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1920009191821 - 2³ = 1920009191813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1920009192821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20058325 + ... + 20153818.

It is an arithmetic number, because the mean of its divisors is an integer number (144763718400).

Almost surely, 2^{1920009191821} is an apocalyptic number.

It is an amenable number.

1920009191821 is a deficient number, since it is larger than the sum of its proper divisors (396210302579).

1920009191821 is a wasteful number, since it uses less digits than its factorization.

1920009191821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40212528.

The product of its (nonzero) digits is 23328, while the sum is 43.

The spelling of 1920009191821 in words is "one trillion, nine hundred twenty billion, nine million, one hundred ninety-one thousand, eight hundred twenty-one".