257155221 has 8 divisors (see below), whose sum is σ = 342994144. Its totient is φ = 171376560.

The previous prime is 257155219. The next prime is 257155231. The reversal of 257155221 is 122551752.

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

It is not a de Polignac number, because 257155221 - 2¹ = 257155219 is a prime.

It is a super-2 number, since 2×257155221² = 132257615375117682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257155201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3931 + ... + 23016.

It is an arithmetic number, because the mean of its divisors is an integer number (42874268).

Almost surely, 2^257155221 is an apocalyptic number.

It is an amenable number.

257155221 is a deficient number, since it is larger than the sum of its proper divisors (85838923).

257155221 is a wasteful number, since it uses less digits than its factorization.

257155221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30131.

The product of its digits is 7000, while the sum is 30.

The square root of 257155221 is about 16036.0600210900. The cubic root of 257155221 is about 635.9140913788.

The spelling of 257155221 in words is "two hundred fifty-seven million, one hundred fifty-five thousand, two hundred twenty-one".