1561138 has 8 divisors (see below), whose sum is σ = 2347632. Its totient is φ = 778596.

The previous prime is 1561123. The next prime is 1561139. The reversal of 1561138 is 8311651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1561139) 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 3 ways as a sum of consecutive naturals, for example, 381 + ... + 1807.

It is an arithmetic number, because the mean of its divisors is an integer number (293454).

2^1561138 is an apocalyptic number.

1561138 is a deficient number, since it is larger than the sum of its proper divisors (786494).

1561138 is a wasteful number, since it uses less digits than its factorization.

1561138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1976.

The product of its digits is 720, while the sum is 25.

The square root of 1561138 is about 1249.4550812254. The cubic root of 1561138 is about 116.0059945376.

Adding to 1561138 its reverse (8311651), we get a palindrome (9872789).

The spelling of 1561138 in words is "one million, five hundred sixty-one thousand, one hundred thirty-eight".