1240857 has 6 divisors (see below), whose sum is σ = 1792362. Its totient is φ = 827232.

The previous prime is 1240831. The next prime is 1240859. The reversal of 1240857 is 7580421.

It can be written as a sum of positive squares in only one way, i.e., 646416 + 594441 = 804^2 + 771^2 .

It is not a de Polignac number, because 1240857 - 2⁶ = 1240793 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1240857.

It is not an unprimeable number, because it can be changed into a prime (1240859) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 68928 + ... + 68945.

It is an arithmetic number, because the mean of its divisors is an integer number (298727).

2^1240857 is an apocalyptic number.

It is an amenable number.

1240857 is a deficient number, since it is larger than the sum of its proper divisors (551505).

1240857 is a wasteful number, since it uses less digits than its factorization.

1240857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137879 (or 137876 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 1240857 is about 1113.9376104612. The cubic root of 1240857 is about 107.4584515839.

The spelling of 1240857 in words is "one million, two hundred forty thousand, eight hundred fifty-seven".