1561389 has 16 divisors (see below), whose sum is σ = 2185920. Its totient is φ = 990080.

The previous prime is 1561367. The next prime is 1561393. The reversal of 1561389 is 9831651.

It is a cyclic number.

It is not a de Polignac number, because 1561389 - 2⁹ = 1560877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11329 + ... + 11465.

It is an arithmetic number, because the mean of its divisors is an integer number (136620).

2^1561389 is an apocalyptic number.

It is an amenable number.

1561389 is a deficient number, since it is larger than the sum of its proper divisors (624531).

1561389 is a wasteful number, since it uses less digits than its factorization.

1561389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300.

The product of its digits is 6480, while the sum is 33.

The square root of 1561389 is about 1249.5555209754. Note that the first 4 decimals coincide. The cubic root of 1561389 is about 116.0122113581.

The spelling of 1561389 in words is "one million, five hundred sixty-one thousand, three hundred eighty-nine".