201868921 has 4 divisors (see below), whose sum is σ = 202105332. Its totient is φ = 201632512.

The previous prime is 201868883. The next prime is 201868949. The reversal of 201868921 is 129868102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 175191696 + 26677225 = 13236^2 + 5165^2 .

It is a cyclic number.

It is not a de Polignac number, because 201868921 - 2⁹ = 201868409 is a prime.

It is a super-2 number, since 2×201868921² = 81502122531408482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201868951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116920 + ... + 118633.

It is an arithmetic number, because the mean of its divisors is an integer number (50526333).

Almost surely, 2^201868921 is an apocalyptic number.

It is an amenable number.

201868921 is a deficient number, since it is larger than the sum of its proper divisors (236411).

201868921 is an equidigital number, since it uses as much as digits as its factorization.

201868921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236410.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 201868921 is about 14208.0583120988. The cubic root of 201868921 is about 586.6194889677.

The spelling of 201868921 in words is "two hundred one million, eight hundred sixty-eight thousand, nine hundred twenty-one".