1555791 has 4 divisors (see below), whose sum is σ = 2074392. Its totient is φ = 1037192.

The previous prime is 1555787. The next prime is 1555793. The reversal of 1555791 is 1975551.

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

It is a cyclic number.

It is not a de Polignac number, because 1555791 - 2² = 1555787 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1555793) 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, 259296 + ... + 259301.

It is an arithmetic number, because the mean of its divisors is an integer number (518598).

2^1555791 is an apocalyptic number.

1555791 is a deficient number, since it is larger than the sum of its proper divisors (518601).

1555791 is an equidigital number, since it uses as much as digits as its factorization.

1555791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518600.

The product of its digits is 7875, while the sum is 33.

The square root of 1555791 is about 1247.3135131153. The cubic root of 1555791 is about 115.8734003287.

It can be divided in two parts, 1555 and 791, that added together give a triangular number (2346 = T₆₈).

The spelling of 1555791 in words is "one million, five hundred fifty-five thousand, seven hundred ninety-one".