201651665520 has 80 divisors (see below), whose sum is σ = 630855292320. Its totient is φ = 53280433152.

The previous prime is 201651665519. The next prime is 201651665533. The reversal of 201651665520 is 25566156102.

It is a happy number.

201651665520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3828039 + ... + 3880358.

It is an arithmetic number, because the mean of its divisors is an integer number (7885691154).

Almost surely, 2^201651665520 is an apocalyptic number.

201651665520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201651665520 is an abundant number, since it is smaller than the sum of its proper divisors (429203626800).

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

201651665520 is a wasteful number, since it uses less digits than its factorization.

201651665520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7708522 (or 7708516 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 39.

The spelling of 201651665520 in words is "two hundred one billion, six hundred fifty-one million, six hundred sixty-five thousand, five hundred twenty".