5691501661 has 4 divisors (see below), whose sum is σ = 5991054400. Its totient is φ = 5391948924.

The previous prime is 5691501659. The next prime is 5691501701. The reversal of 5691501661 is 1661051965.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1661051965 = 5 ⋅332210393.

It is a cyclic number.

It is not a de Polignac number, because 5691501661 - 2¹ = 5691501659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5691501631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149776341 + ... + 149776378.

It is an arithmetic number, because the mean of its divisors is an integer number (1497763600).

Almost surely, 2^5691501661 is an apocalyptic number.

It is an amenable number.

5691501661 is a deficient number, since it is larger than the sum of its proper divisors (299552739).

5691501661 is a wasteful number, since it uses less digits than its factorization.

5691501661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299552738.

The product of its (nonzero) digits is 48600, while the sum is 40.

The square root of 5691501661 is about 75442.0417340358. The cubic root of 5691501661 is about 1785.4277848088.

The spelling of 5691501661 in words is "five billion, six hundred ninety-one million, five hundred one thousand, six hundred sixty-one".