2101255021 has 4 divisors (see below), whose sum is σ = 2120532700. Its totient is φ = 2081977344.

The previous prime is 2101255019. The next prime is 2101255103. The reversal of 2101255021 is 1205521012.

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 1553226921 + 548028100 = 39411^2 + 23410^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101255021 - 2¹ = 2101255019 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 2101255021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101255421) 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, 9638676 + ... + 9638893.

It is an arithmetic number, because the mean of its divisors is an integer number (530133175).

Almost surely, 2^2101255021 is an apocalyptic number.

It is an amenable number.

2101255021 is a deficient number, since it is larger than the sum of its proper divisors (19277679).

2101255021 is a wasteful number, since it uses less digits than its factorization.

2101255021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19277678.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 2101255021 is about 45839.4483060169. The cubic root of 2101255021 is about 1280.8342179541.

Adding to 2101255021 its reverse (1205521012), we get a palindrome (3306776033).

The spelling of 2101255021 in words is "two billion, one hundred one million, two hundred fifty-five thousand, twenty-one".