1561516625 has 16 divisors (see below), whose sum is σ = 1949920128. Its totient is φ = 1248478000.

The previous prime is 1561516609. The next prime is 1561516643. The reversal of 1561516625 is 5266151651.

It is a happy number.

It is not a de Polignac number, because 1561516625 - 2⁴ = 1561516609 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 330530 + ... + 335220.

It is an arithmetic number, because the mean of its divisors is an integer number (121870008).

Almost surely, 2^1561516625 is an apocalyptic number.

It is an amenable number.

1561516625 is a deficient number, since it is larger than the sum of its proper divisors (388403503).

1561516625 is an equidigital number, since it uses as much as digits as its factorization.

1561516625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7369 (or 7359 counting only the distinct ones).

The product of its digits is 54000, while the sum is 38.

The square root of 1561516625 is about 39516.0299751886. The cubic root of 1561516625 is about 1160.1537214534.

The spelling of 1561516625 in words is "one billion, five hundred sixty-one million, five hundred sixteen thousand, six hundred twenty-five".