253939993 has 4 divisors (see below), whose sum is σ = 253978468. Its totient is φ = 253901520.

The previous prime is 253939951. The next prime is 253940021. The reversal of 253939993 is 399939352.

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 76597504 + 177342489 = 8752^2 + 13317^2 .

It is a cyclic number.

It is not a de Polignac number, because 253939993 - 2¹⁷ = 253808921 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 253939993.

It is not an unprimeable number, because it can be changed into a prime (253939193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6546 + ... + 23467.

It is an arithmetic number, because the mean of its divisors is an integer number (63494617).

Almost surely, 2^253939993 is an apocalyptic number.

It is an amenable number.

253939993 is a deficient number, since it is larger than the sum of its proper divisors (38475).

253939993 is an equidigital number, since it uses as much as digits as its factorization.

253939993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38474.

The product of its digits is 1771470, while the sum is 52.

The square root of 253939993 is about 15935.4947522818. The cubic root of 253939993 is about 633.2526770479.

The spelling of 253939993 in words is "two hundred fifty-three million, nine hundred thirty-nine thousand, nine hundred ninety-three".