257291221 has 8 divisors (see below), whose sum is σ = 280865088. Its totient is φ = 233748000.

The previous prime is 257291191. The next prime is 257291267. The reversal of 257291221 is 122192752.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257291221 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 (257291921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12136 + ... + 25726.

It is an arithmetic number, because the mean of its divisors is an integer number (35108136).

Almost surely, 2^257291221 is an apocalyptic number.

It is an amenable number.

257291221 is a deficient number, since it is larger than the sum of its proper divisors (23573867).

257291221 is a wasteful number, since it uses less digits than its factorization.

257291221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15323.

The product of its digits is 5040, while the sum is 31.

The square root of 257291221 is about 16040.2999036801. The cubic root of 257291221 is about 636.0261755309.

The spelling of 257291221 in words is "two hundred fifty-seven million, two hundred ninety-one thousand, two hundred twenty-one".