5661551665 has 32 divisors (see below), whose sum is σ = 8506757376. Its totient is φ = 3514076160.

The previous prime is 5661551629. The next prime is 5661551681.

5661551665 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 5661551665 - 2⁹ = 5661551153 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58149 + ... + 121261.

It is an arithmetic number, because the mean of its divisors is an integer number (265836168).

Almost surely, 2^5661551665 is an apocalyptic number.

5661551665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

5661551665 is a deficient number, since it is larger than the sum of its proper divisors (2845205711).

5661551665 is a wasteful number, since it uses less digits than its factorization.

5661551665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63369.

The product of its digits is 810000, while the sum is 46.

The square root of 5661551665 is about 75243.2831886010. The cubic root of 5661551665 is about 1782.2904975507.

The spelling of 5661551665 in words is "five billion, six hundred sixty-one million, five hundred fifty-one thousand, six hundred sixty-five".