1801501818156 has 144 divisors (see below), whose sum is σ = 4745294281728. Its totient is φ = 575632137600.

The previous prime is 1801501818113. The next prime is 1801501818197. The reversal of 1801501818156 is 6518181051081.

1801501818156 is a `hidden beast` number, since 1 + 80 + 1 + 501 + 8 + 18 + 1 + 56 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 81420111 + ... + 81442233.

It is an arithmetic number, because the mean of its divisors is an integer number (32953432512).

Almost surely, 2^{1801501818156} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1801501818156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2372647140864).

1801501818156 is an abundant number, since it is smaller than the sum of its proper divisors (2943792463572).

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

1801501818156 is a wasteful number, since it uses less digits than its factorization.

1801501818156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22852 (or 22847 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 45.

The spelling of 1801501818156 in words is "one trillion, eight hundred one billion, five hundred one million, eight hundred eighteen thousand, one hundred fifty-six".