1561329 has 32 divisors (see below), whose sum is σ = 2887680. Its totient is φ = 810000.

The previous prime is 1561303. The next prime is 1561337. The reversal of 1561329 is 9231651.

It is not a de Polignac number, because 1561329 - 2⁹ = 1560817 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 31 ways as a sum of consecutive naturals, for example, 1704 + ... + 2454.

It is an arithmetic number, because the mean of its divisors is an integer number (90240).

2^1561329 is an apocalyptic number.

It is an amenable number.

1561329 is a deficient number, since it is larger than the sum of its proper divisors (1326351).

1561329 is a wasteful number, since it uses less digits than its factorization.

1561329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778 (or 772 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 1561329 is about 1249.5315122077. The cubic root of 1561329 is about 116.0107253262.

It can be divided in two parts, 156 and 1329, that added together give a triangular number (1485 = T₅₄).

The spelling of 1561329 in words is "one million, five hundred sixty-one thousand, three hundred twenty-nine".