201981311 has 4 divisors (see below), whose sum is σ = 230835792. Its totient is φ = 173126832.

The previous prime is 201981289. The next prime is 201981313. The reversal of 201981311 is 113189102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 201981311 - 2²⁶ = 134872447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201981313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14427230 + ... + 14427243.

It is an arithmetic number, because the mean of its divisors is an integer number (57708948).

Almost surely, 2^201981311 is an apocalyptic number.

201981311 is a deficient number, since it is larger than the sum of its proper divisors (28854481).

201981311 is an equidigital number, since it uses as much as digits as its factorization.

201981311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28854480.

The product of its (nonzero) digits is 432, while the sum is 26.

The square root of 201981311 is about 14212.0129116181. The cubic root of 201981311 is about 586.7283350650.

The spelling of 201981311 in words is "two hundred one million, nine hundred eighty-one thousand, three hundred eleven".