201825721 has 4 divisors (see below), whose sum is σ = 202544244. Its totient is φ = 201107200.

The previous prime is 201825709. The next prime is 201825727. The reversal of 201825721 is 127528102.

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 98010000 + 103815721 = 9900^2 + 10189^2 .

It is a cyclic number.

It is not a de Polignac number, because 201825721 - 2¹³ = 201817529 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 201825721.

It is not an unprimeable number, because it can be changed into a prime (201825727) 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, 358840 + ... + 359401.

It is an arithmetic number, because the mean of its divisors is an integer number (50636061).

Almost surely, 2^201825721 is an apocalyptic number.

It is an amenable number.

201825721 is a deficient number, since it is larger than the sum of its proper divisors (718523).

201825721 is an equidigital number, since it uses as much as digits as its factorization.

201825721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718522.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 201825721 is about 14206.5379667250. The cubic root of 201825721 is about 586.5776404095.

The spelling of 201825721 in words is "two hundred one million, eight hundred twenty-five thousand, seven hundred twenty-one".