5661512321 has 4 divisors (see below), whose sum is σ = 5666721792. Its totient is φ = 5656302852.

The previous prime is 5661512293. The next prime is 5661512359. The reversal of 5661512321 is 1232151665.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 5661512321 - 2³⁰ = 4587770497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5661512371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2603105 + ... + 2605278.

It is an arithmetic number, because the mean of its divisors is an integer number (1416680448).

Almost surely, 2^5661512321 is an apocalyptic number.

It is an amenable number.

5661512321 is a deficient number, since it is larger than the sum of its proper divisors (5209471).

5661512321 is a wasteful number, since it uses less digits than its factorization.

5661512321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5209470.

The product of its digits is 10800, while the sum is 32.

The square root of 5661512321 is about 75243.0217428832. The cubic root of 5661512321 is about 1782.2863689653.

Adding to 5661512321 its reverse (1232151665), we get a palindrome (6893663986).

The spelling of 5661512321 in words is "five billion, six hundred sixty-one million, five hundred twelve thousand, three hundred twenty-one".