3061661561 has 20 divisors (see below), whose sum is σ = 3578871312. Its totient is φ = 2619035496.

The previous prime is 3061661557. The next prime is 3061661567. The reversal of 3061661561 is 1651661603.

It is not a de Polignac number, because 3061661561 - 2² = 3061661557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (3061661567) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1638950 + ... + 1640816.

Almost surely, 2^3061661561 is an apocalyptic number.

It is an amenable number.

3061661561 is a deficient number, since it is larger than the sum of its proper divisors (517209751).

3061661561 is an frugal number, since it uses more digits than its factorization.

3061661561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2578 (or 2557 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 3061661561 is about 55332.2831717615. The cubic root of 3061661561 is about 1452.0638957847.

The spelling of 3061661561 in words is "three billion, sixty-one million, six hundred sixty-one thousand, five hundred sixty-one".