1561140 has 144 divisors (see below), whose sum is σ = 5745600. Its totient is φ = 350784.

The previous prime is 1561139. The next prime is 1561151. The reversal of 1561140 is 411651.

1561140 is a `hidden beast` number, since 15 + 611 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 26431 + ... + 26489.

It is an arithmetic number, because the mean of its divisors is an integer number (39900).

2^1561140 is an apocalyptic number.

1561140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2872800).

1561140 is an abundant number, since it is smaller than the sum of its proper divisors (4184460).

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

1561140 is a wasteful number, since it uses less digits than its factorization.

1561140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1561140 is about 1249.4558815741. The cubic root of 1561140 is about 116.0060440767.

Adding to 1561140 its reverse (411651), we get a palindrome (1972791).

It can be divided in two parts, 15611 and 40, that added together give a palindrome (15651).

The spelling of 1561140 in words is "one million, five hundred sixty-one thousand, one hundred forty".