201601499991 has 8 divisors (see below), whose sum is σ = 268811783424. Its totient is φ = 134396108280.

The previous prime is 201601499987. The next prime is 201601500017. The reversal of 201601499991 is 199994106102.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 201601499991 - 2² = 201601499987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201601499951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1125661 + ... + 1292406.

It is an arithmetic number, because the mean of its divisors is an integer number (33601472928).

Almost surely, 2^201601499991 is an apocalyptic number.

201601499991 is a deficient number, since it is larger than the sum of its proper divisors (67210283433).

201601499991 is a wasteful number, since it uses less digits than its factorization.

201601499991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2445861.

The product of its (nonzero) digits is 314928, while the sum is 51.

The spelling of 201601499991 in words is "two hundred one billion, six hundred one million, four hundred ninety-nine thousand, nine hundred ninety-one".