1561937841 has 6 divisors (see below), whose sum is σ = 2256132450. Its totient is φ = 1041291888.

The previous prime is 1561937833. The next prime is 1561937851. The reversal of 1561937841 is 1487391651.

1561937841 is a `hidden beast` number, since 1 + 561 + 9 + 3 + 7 + 84 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 979439616 + 582498225 = 31296^2 + 24135^2 .

It is not a de Polignac number, because 1561937841 - 2³ = 1561937833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1561937851) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86774316 + ... + 86774333.

It is an arithmetic number, because the mean of its divisors is an integer number (376022075).

Almost surely, 2^1561937841 is an apocalyptic number.

It is an amenable number.

1561937841 is a deficient number, since it is larger than the sum of its proper divisors (694194609).

1561937841 is a wasteful number, since it uses less digits than its factorization.

1561937841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173548655 (or 173548652 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 1561937841 is about 39521.3593010160. The cubic root of 1561937841 is about 1160.2580284604.

The spelling of 1561937841 in words is "one billion, five hundred sixty-one million, nine hundred thirty-seven thousand, eight hundred forty-one".