201556361664 has 504 divisors, whose sum is σ = 713261797248. Its totient is φ = 56239142400.

The previous prime is 201556361647. The next prime is 201556361681. The reversal of 201556361664 is 466163655102.

201556361664 is a `hidden beast` number, since 2 + 0 + 1 + 5 + 5 + 636 + 1 + 6 + 6 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (201556361647) and next prime (201556361681).

It is a tau number, because it is divible by the number of its divisors (504).

It is a congruent number.

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 71 ways as a sum of consecutive naturals, for example, 32764989 + ... + 32771139.

Almost surely, 2^201556361664 is an apocalyptic number.

201556361664 is a gapful number since it is divisible by the number (24) 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 201556361664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (356630898624).

201556361664 is an abundant number, since it is smaller than the sum of its proper divisors (511705435584).

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

201556361664 is an equidigital number, since it uses as much as digits as its factorization.

201556361664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6235 (or 6206 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 45.

The spelling of 201556361664 in words is "two hundred one billion, five hundred fifty-six million, three hundred sixty-one thousand, six hundred sixty-four".