253021309 has 4 divisors (see below), whose sum is σ = 266338240. Its totient is φ = 239704380.

The previous prime is 253021297. The next prime is 253021313. The reversal of 253021309 is 903120352.

It is a happy number.

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 not a de Polignac number, because 253021309 - 2⁵ = 253021277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253021339) 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, 6658437 + ... + 6658474.

It is an arithmetic number, because the mean of its divisors is an integer number (66584560).

Almost surely, 2^253021309 is an apocalyptic number.

It is an amenable number.

253021309 is a deficient number, since it is larger than the sum of its proper divisors (13316931).

253021309 is a wasteful number, since it uses less digits than its factorization.

253021309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13316930.

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 253021309 is about 15906.6435491589. The cubic root of 253021309 is about 632.4881105109.

The spelling of 253021309 in words is "two hundred fifty-three million, twenty-one thousand, three hundred nine".