1242557 has 4 divisors (see below), whose sum is σ = 1244796. Its totient is φ = 1240320.

The previous prime is 1242517. The next prime is 1242569. The reversal of 1242557 is 7552421.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7552421 = 283 ⋅26687.

It can be written as a sum of positive squares in 2 ways, for example, as 568516 + 674041 = 754^2 + 821^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1242557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242517) 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, 413 + ... + 1629.

It is an arithmetic number, because the mean of its divisors is an integer number (311199).

2^1242557 is an apocalyptic number.

It is an amenable number.

1242557 is a deficient number, since it is larger than the sum of its proper divisors (2239).

1242557 is a wasteful number, since it uses less digits than its factorization.

1242557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2238.

The product of its digits is 2800, while the sum is 26.

The square root of 1242557 is about 1114.7004081815. The cubic root of 1242557 is about 107.5075026312.

Adding to 1242557 its reverse (7552421), we get a palindrome (8794978).

The spelling of 1242557 in words is "one million, two hundred forty-two thousand, five hundred fifty-seven".