201010021 has 4 divisors (see below), whose sum is σ = 201088332. Its totient is φ = 200931712.

The previous prime is 201010001. The next prime is 201010027. The reversal of 201010021 is 120010102.

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 121550625 + 79459396 = 11025^2 + 8914^2 .

It is a cyclic number.

It is not a de Polignac number, because 201010021 - 2⁹ = 201009509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201009986 and 201010013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201010027) 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, 35170 + ... + 40483.

It is an arithmetic number, because the mean of its divisors is an integer number (50272083).

Almost surely, 2^201010021 is an apocalyptic number.

It is an amenable number.

201010021 is a deficient number, since it is larger than the sum of its proper divisors (78311).

201010021 is an equidigital number, since it uses as much as digits as its factorization.

201010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78310.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 201010021 is about 14177.8002877738. The cubic root of 201010021 is about 585.7863348750.

Adding to 201010021 its reverse (120010102), we get a palindrome (321020123).

The spelling of 201010021 in words is "two hundred one million, ten thousand, twenty-one".