1811920991892 has 36 divisors (see below), whose sum is σ = 4647103153728. Its totient is φ = 549066966800.

The previous prime is 1811920991873. The next prime is 1811920991897. The reversal of 1811920991892 is 2981990291181.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1811920991897) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 623938284 + ... + 623941187.

Almost surely, 2^{1811920991892} is an apocalyptic number.

1811920991892 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1811920991892 is an abundant number, since it is smaller than the sum of its proper divisors (2835182161836).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1811920991892 is a wasteful number, since it uses less digits than its factorization.

1811920991892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1247879500 (or 1247879487 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 60.

The spelling of 1811920991892 in words is "one trillion, eight hundred eleven billion, nine hundred twenty million, nine hundred ninety-one thousand, eight hundred ninety-two".