201518101980 has 144 divisors (see below), whose sum is σ = 658437159744. Its totient is φ = 49593553920.

The previous prime is 201518101969. The next prime is 201518102011. The reversal of 201518101980 is 89101815102.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17794720 + ... + 17806040.

It is an arithmetic number, because the mean of its divisors is an integer number (4572480276).

Almost surely, 2^201518101980 is an apocalyptic number.

201518101980 is a gapful number since it is divisible by the number (20) 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 201518101980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329218579872).

201518101980 is an abundant number, since it is smaller than the sum of its proper divisors (456919057764).

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

201518101980 is a wasteful number, since it uses less digits than its factorization.

201518101980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18956 (or 18951 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 36.

The spelling of 201518101980 in words is "two hundred one billion, five hundred eighteen million, one hundred one thousand, nine hundred eighty".