5661561511 has 4 divisors (see below), whose sum is σ = 5856787800. Its totient is φ = 5466335224.

The previous prime is 5661561487. The next prime is 5661561553. The reversal of 5661561511 is 1151651665.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 5661561511 - 2¹³ = 5661553319 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5661561011) 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, 97613101 + ... + 97613158.

It is an arithmetic number, because the mean of its divisors is an integer number (1464196950).

Almost surely, 2^5661561511 is an apocalyptic number.

5661561511 is a deficient number, since it is larger than the sum of its proper divisors (195226289).

5661561511 is a wasteful number, since it uses less digits than its factorization.

5661561511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195226288.

The product of its digits is 27000, while the sum is 37.

The square root of 5661561511 is about 75243.3486163395. The cubic root of 5661561511 is about 1782.2915307435.

The spelling of 5661561511 in words is "five billion, six hundred sixty-one million, five hundred sixty-one thousand, five hundred eleven".