1561384 has 24 divisors (see below), whose sum is σ = 3219930. Its totient is φ = 709280.

The previous prime is 1561367. The next prime is 1561393. The reversal of 1561384 is 4831651.

It can be written as a sum of positive squares in only one way, i.e., 1258884 + 302500 = 1122^2 + 550^2 .

It is a nialpdrome in base 11.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 162 + ... + 1774.

2^1561384 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1609965).

1561384 is an abundant number, since it is smaller than the sum of its proper divisors (1658546).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561384 is a wasteful number, since it uses less digits than its factorization.

1561384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1641 (or 1626 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 1561384 is about 1249.5535202623. The cubic root of 1561384 is about 116.0120875236.

It can be divided in two parts, 156 and 1384, that added together give a triangular number (1540 = T₅₅).

The spelling of 1561384 in words is "one million, five hundred sixty-one thousand, three hundred eighty-four".