1561312340 has 24 divisors (see below), whose sum is σ = 3747149952. Its totient is φ = 535307040.

The previous prime is 1561312331. The next prime is 1561312343. The reversal of 1561312340 is 432131651.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561312343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5575976 + ... + 5576255.

It is an arithmetic number, because the mean of its divisors is an integer number (156131248).

Almost surely, 2^1561312340 is an apocalyptic number.

1561312340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561312340 is an abundant number, since it is smaller than the sum of its proper divisors (2185837612).

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

1561312340 is a wasteful number, since it uses less digits than its factorization.

1561312340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11152247 (or 11152245 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 1561312340 is about 39513.4450535511. The cubic root of 1561312340 is about 1160.1031269789.

Adding to 1561312340 its reverse (432131651), we get a palindrome (1993443991).

The spelling of 1561312340 in words is "one billion, five hundred sixty-one million, three hundred twelve thousand, three hundred forty".