257240765 has 8 divisors (see below), whose sum is σ = 316218168. Its totient is φ = 200773120.

The previous prime is 257240743. The next prime is 257240773. The reversal of 257240765 is 567042752.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1592644 + 255648121 = 1262^2 + 15989^2 .

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

It is not a de Polignac number, because 257240765 - 2¹⁶ = 257175229 is a prime.

It is a super-2 number, since 2×257240765² = 132345622355570450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 627212 + ... + 627621.

It is an arithmetic number, because the mean of its divisors is an integer number (39527271).

Almost surely, 2^257240765 is an apocalyptic number.

It is an amenable number.

257240765 is a deficient number, since it is larger than the sum of its proper divisors (58977403).

257240765 is a wasteful number, since it uses less digits than its factorization.

257240765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1254879.

The product of its (nonzero) digits is 117600, while the sum is 38.

The square root of 257240765 is about 16038.7270380165. The cubic root of 257240765 is about 635.9845969201.

The spelling of 257240765 in words is "two hundred fifty-seven million, two hundred forty thousand, seven hundred sixty-five".