1255639 has 16 divisors (see below), whose sum is σ = 1635840. Its totient is φ = 934560.

The previous prime is 1255633. The next prime is 1255651. The reversal of 1255639 is 9365521.

It is not a de Polignac number, because 1255639 - 2¹¹ = 1253591 is a prime.

It is a Duffinian number.

1255639 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1255639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1255633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1417 + ... + 2125.

It is an arithmetic number, because the mean of its divisors is an integer number (102240).

2^1255639 is an apocalyptic number.

1255639 is the 709-th heptagonal number.

1255639 is a deficient number, since it is larger than the sum of its proper divisors (380201).

1255639 is a wasteful number, since it uses less digits than its factorization.

1255639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750.

The product of its digits is 8100, while the sum is 31.

The square root of 1255639 is about 1120.5529884838. The cubic root of 1255639 is about 107.8834762912.

The spelling of 1255639 in words is "one million, two hundred fifty-five thousand, six hundred thirty-nine".