201421823 has 4 divisors (see below), whose sum is σ = 201822768. Its totient is φ = 201020880.

The previous prime is 201421799. The next prime is 201421841. The reversal of 201421823 is 328124102.

It is a happy number.

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 201421823 - 2¹⁴ = 201405439 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 (201421853) 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, 199718 + ... + 200723.

It is an arithmetic number, because the mean of its divisors is an integer number (50455692).

Almost surely, 2^201421823 is an apocalyptic number.

201421823 is a deficient number, since it is larger than the sum of its proper divisors (400945).

201421823 is an equidigital number, since it uses as much as digits as its factorization.

201421823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400944.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 201421823 is about 14192.3156320595. The cubic root of 201421823 is about 586.1860884770.

Adding to 201421823 its reverse (328124102), we get a palindrome (529545925).

The spelling of 201421823 in words is "two hundred one million, four hundred twenty-one thousand, eight hundred twenty-three".