1820051387172 has 144 divisors (see below), whose sum is σ = 4827684144192. Its totient is φ = 599518402560.

The previous prime is 1820051387137. The next prime is 1820051387173. The reversal of 1820051387172 is 2717831500281.

1820051387172 is a `hidden beast` number, since 1 + 8 + 200 + 51 + 387 + 17 + 2 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1820051387173) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36990147 + ... + 37039317.

Almost surely, 2^{1820051387172} is an apocalyptic number.

1820051387172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1820051387172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2413842072096).

1820051387172 is an abundant number, since it is smaller than the sum of its proper divisors (3007632757020).

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

1820051387172 is a wasteful number, since it uses less digits than its factorization.

1820051387172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49640 (or 49626 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 45.

The spelling of 1820051387172 in words is "one trillion, eight hundred twenty billion, fifty-one million, three hundred eighty-seven thousand, one hundred seventy-two".