201021005 has 8 divisors (see below), whose sum is σ = 255415032. Its totient is φ = 151356928.

The previous prime is 201020987. The next prime is 201021043. The reversal of 201021005 is 500120102.

It can be written as a sum of positive squares in 4 ways, for example, as 11600836 + 189420169 = 3406^2 + 13763^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 201021005 - 2¹⁸ = 200758861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1182392 + ... + 1182561.

It is an arithmetic number, because the mean of its divisors is an integer number (31926879).

Almost surely, 2^201021005 is an apocalyptic number.

It is an amenable number.

201021005 is a deficient number, since it is larger than the sum of its proper divisors (54394027).

201021005 is a wasteful number, since it uses less digits than its factorization.

201021005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2364975.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 201021005 is about 14178.1876486383. The cubic root of 201021005 is about 585.7970045916.

Adding to 201021005 its reverse (500120102), we get a palindrome (701141107).

The spelling of 201021005 in words is "two hundred one million, twenty-one thousand, five".