1561136860 has 24 divisors (see below), whose sum is σ = 3471234480. Its totient is φ = 587721984.

The previous prime is 1561136851. The next prime is 1561136861. The reversal of 1561136860 is 686311651.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561136861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2295450 + ... + 2296129.

It is an arithmetic number, because the mean of its divisors is an integer number (144634770).

Almost surely, 2^1561136860 is an apocalyptic number.

1561136860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561136860 is an abundant number, since it is smaller than the sum of its proper divisors (1910097620).

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

1561136860 is a wasteful number, since it uses less digits than its factorization.

1561136860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4591605 (or 4591603 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 1561136860 is about 39511.2244811522. The cubic root of 1561136860 is about 1160.0596630034.

The spelling of 1561136860 in words is "one billion, five hundred sixty-one million, one hundred thirty-six thousand, eight hundred sixty".