1256642 has 8 divisors (see below), whose sum is σ = 1903932. Its totient is φ = 622000.

The previous prime is 1256621. The next prime is 1256659. The reversal of 1256642 is 2466521.

It is a Cunningham number, because it is equal to 1121²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 1256641 + 1 = 1121^2 + 1^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2909 + ... + 3312.

2^1256642 is an apocalyptic number.

1256642 is a deficient number, since it is larger than the sum of its proper divisors (647290).

1256642 is a wasteful number, since it uses less digits than its factorization.

1256642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6324.

The product of its digits is 2880, while the sum is 26.

The square root of 1256642 is about 1121.0004460302. Note that the first 3 decimals coincide. The cubic root of 1256642 is about 107.9121942926.

The spelling of 1256642 in words is "one million, two hundred fifty-six thousand, six hundred forty-two".