239638257 has 20 divisors (see below), whose sum is σ = 359856420. Its totient is φ = 158920704.

The previous prime is 239638249. The next prime is 239638261. The reversal of 239638257 is 752836932.

239638257 is a `hidden beast` number, since 2 + 3 + 9 + 638 + 2 + 5 + 7 = 666.

239638257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 38452401 + 201185856 = 6201^2 + 14184^2 .

It is not a de Polignac number, because 239638257 - 2³ = 239638249 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (239638207) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7969 + ... + 23297.

It is an arithmetic number, because the mean of its divisors is an integer number (17992821).

Almost surely, 2^239638257 is an apocalyptic number.

239638257 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

239638257 is a deficient number, since it is larger than the sum of its proper divisors (120218163).

239638257 is a wasteful number, since it uses less digits than its factorization.

239638257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15534 (or 15525 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 239638257 is about 15480.2537769896. The cubic root of 239638257 is about 621.1341165206.

The spelling of 239638257 in words is "two hundred thirty-nine million, six hundred thirty-eight thousand, two hundred fifty-seven".