861257 has 4 divisors (see below), whose sum is σ = 863940. Its totient is φ = 858576.

The previous prime is 861239. The next prime is 861293. The reversal of 861257 is 752168.

861257 is nontrivially palindromic in base 5.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 602176 + 259081 = 776^2 + 509^2 .

It is a cyclic number.

It is not a de Polignac number, because 861257 - 2⁸ = 861001 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (861857) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 782 + ... + 1527.

It is an arithmetic number, because the mean of its divisors is an integer number (215985).

2⁸⁶¹²⁵⁷ is an apocalyptic number.

It is an amenable number.

861257 is a deficient number, since it is larger than the sum of its proper divisors (2683).

861257 is a wasteful number, since it uses less digits than its factorization.

861257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2682.

The product of its digits is 3360, while the sum is 29.

The square root of 861257 is about 928.0393310631. The cubic root of 861257 is about 95.1431636474.

The spelling of 861257 in words is "eight hundred sixty-one thousand, two hundred fifty-seven".