201684521 has 4 divisors (see below), whose sum is σ = 207135492. Its totient is φ = 196233552.

The previous prime is 201684503. The next prime is 201684523. The reversal of 201684521 is 125486102.

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 178596496 + 23088025 = 13364^2 + 4805^2 .

It is a cyclic number.

It is not a de Polignac number, because 201684521 - 2²² = 197490217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201684523) 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, 2725430 + ... + 2725503.

It is an arithmetic number, because the mean of its divisors is an integer number (51783873).

Almost surely, 2^201684521 is an apocalyptic number.

It is an amenable number.

201684521 is a deficient number, since it is larger than the sum of its proper divisors (5450971).

201684521 is an equidigital number, since it uses as much as digits as its factorization.

201684521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5450970.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 201684521 is about 14201.5675543230. The cubic root of 201684521 is about 586.4408159502.

The spelling of 201684521 in words is "two hundred one million, six hundred eighty-four thousand, five hundred twenty-one".