201609980100 has 189 divisors, whose sum is σ = 656335090173. Its totient is φ = 53730332640.

The previous prime is 201609980093. The next prime is 201609980111. The reversal of 201609980100 is 1089906102.

The square root of 201609980100 is 449010.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 72579592836 + 129030387264 = 269406^2 + 359208^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 121231869 + ... + 121233531.

Almost surely, 2^201609980100 is an apocalyptic number.

201609980100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

201609980100 is the 449010-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 201609980100

201609980100 is an abundant number, since it is smaller than the sum of its proper divisors (454725110073).

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

201609980100 is an frugal number, since it uses more digits than its factorization.

201609980100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3358 (or 1673 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

Multiplying 201609980100 by its sum of digits (36), we get a square (7257959283600 = 2694060²).

201609980100 divided by its sum of digits (36) gives a square (5600277225 = 74835²).

The spelling of 201609980100 in words is "two hundred one billion, six hundred nine million, nine hundred eighty thousand, one hundred".