201891623 has 4 divisors (see below), whose sum is σ = 208404288. Its totient is φ = 195378960.

The previous prime is 201891611. The next prime is 201891661. The reversal of 201891623 is 326198102.

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 201891623 - 2¹² = 201887527 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 201891623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201891673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3256286 + ... + 3256347.

It is an arithmetic number, because the mean of its divisors is an integer number (52101072).

Almost surely, 2^201891623 is an apocalyptic number.

201891623 is a deficient number, since it is larger than the sum of its proper divisors (6512665).

201891623 is an equidigital number, since it uses as much as digits as its factorization.

201891623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6512664.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 201891623 is about 14208.8572024635. The cubic root of 201891623 is about 586.6414783794.

It can be divided in two parts, 20189 and 1623, that added together give a palindrome (21812).

The spelling of 201891623 in words is "two hundred one million, eight hundred ninety-one thousand, six hundred twenty-three".