257291005 has 8 divisors (see below), whose sum is σ = 326911032. Its totient is φ = 193724928.

The previous prime is 257291003. The next prime is 257291009. The reversal of 257291005 is 500192752.

It can be written as a sum of positive squares in 4 ways, for example, as 3175524 + 254115481 = 1782^2 + 15941^2 .

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

It is not a de Polignac number, because 257291005 - 2¹ = 257291003 is a prime.

It is a super-2 number, since 2×257291005² = 132397322507820050, 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 (257291003) 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, 1513392 + ... + 1513561.

It is an arithmetic number, because the mean of its divisors is an integer number (40863879).

Almost surely, 2^257291005 is an apocalyptic number.

It is an amenable number.

257291005 is a deficient number, since it is larger than the sum of its proper divisors (69620027).

257291005 is a wasteful number, since it uses less digits than its factorization.

257291005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3026975.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 257291005 is about 16040.2931706375. The cubic root of 257291005 is about 636.0259975463.

The spelling of 257291005 in words is "two hundred fifty-seven million, two hundred ninety-one thousand, five".