253021021 has 4 divisors (see below), whose sum is σ = 276022944. Its totient is φ = 230019100.

The previous prime is 253021019. The next prime is 253021031. The reversal of 253021021 is 120120352.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 253021021 - 2¹ = 253021019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 253020986 and 253021004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253021031) 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, 11500945 + ... + 11500966.

It is an arithmetic number, because the mean of its divisors is an integer number (69005736).

Almost surely, 2^253021021 is an apocalyptic number.

It is an amenable number.

253021021 is a deficient number, since it is larger than the sum of its proper divisors (23001923).

253021021 is a wasteful number, since it uses less digits than its factorization.

253021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23001922.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 253021021 is about 15906.6344963352. The cubic root of 253021021 is about 632.4878705356.

Adding to 253021021 its reverse (120120352), we get a palindrome (373141373).

The spelling of 253021021 in words is "two hundred fifty-three million, twenty-one thousand, twenty-one".