201601556001 has 24 divisors (see below), whose sum is σ = 296615686016. Its totient is φ = 131912051040.

The previous prime is 201601555919. The next prime is 201601556017. The reversal of 201601556001 is 100655106102.

It is a happy number.

201601556001 is a `hidden beast` number, since 2 + 0 + 1 + 6 + 0 + 1 + 55 + 600 + 1 = 666.

201601556001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 201601556001 - 2³³ = 193011621409 is a prime.

It is a super-2 number, since 2×201601556001² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (201601558001) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 142375 + ... + 650748.

Almost surely, 2^201601556001 is an apocalyptic number.

It is an amenable number.

201601556001 is a deficient number, since it is larger than the sum of its proper divisors (95014130015).

201601556001 is a wasteful number, since it uses less digits than its factorization.

201601556001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 793653 (or 793650 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The spelling of 201601556001 in words is "two hundred one billion, six hundred one million, five hundred fifty-six thousand, one".