20181821192 has 32 divisors (see below), whose sum is σ = 41310013080. Its totient is φ = 9187084800.

The previous prime is 20181821171. The next prime is 20181821203. The reversal of 20181821192 is 29112818102.

It can be written as a sum of positive squares in 4 ways, for example, as 12672905476 + 7508915716 = 112574^2 + 86654^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1321559 + ... + 1336742.

Almost surely, 2^20181821192 is an apocalyptic number.

It is an amenable number.

20181821192 is an abundant number, since it is smaller than the sum of its proper divisors (21128191888).

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

20181821192 is a wasteful number, since it uses less digits than its factorization.

20181821192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2658393 (or 2658389 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 35.

The spelling of 20181821192 in words is "twenty billion, one hundred eighty-one million, eight hundred twenty-one thousand, one hundred ninety-two".