253244021 has 4 divisors (see below), whose sum is σ = 260088492. Its totient is φ = 246399552.

The previous prime is 253243999. The next prime is 253244029. The reversal of 253244021 is 120442352.

It is a happy number.

253244021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 229371025 + 23872996 = 15145^2 + 4886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-253244021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253244029) 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, 3422180 + ... + 3422253.

It is an arithmetic number, because the mean of its divisors is an integer number (65022123).

Almost surely, 2^253244021 is an apocalyptic number.

It is an amenable number.

253244021 is a deficient number, since it is larger than the sum of its proper divisors (6844471).

253244021 is an equidigital number, since it uses as much as digits as its factorization.

253244021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6844470.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 253244021 is about 15913.6426062671. The cubic root of 253244021 is about 632.6736303040.

Adding to 253244021 its reverse (120442352), we get a palindrome (373686373).

The spelling of 253244021 in words is "two hundred fifty-three million, two hundred forty-four thousand, twenty-one".