6665150561 has 4 divisors (see below), whose sum is σ = 6683716800. Its totient is φ = 6646584324.

The previous prime is 6665150549. The next prime is 6665150617. The reversal of 6665150561 is 1650515666.

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: 1650515666 = 2 ⋅825257833.

It is a cyclic number.

It is not a de Polignac number, because 6665150561 - 2³⁰ = 5591408737 is a prime.

It is a super-2 number, since 2×6665150561² = 88848464001597229442, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6665150461) 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, 9282581 + ... + 9283298.

It is an arithmetic number, because the mean of its divisors is an integer number (1670929200).

Almost surely, 2^6665150561 is an apocalyptic number.

It is an amenable number.

6665150561 is a deficient number, since it is larger than the sum of its proper divisors (18566239).

6665150561 is a wasteful number, since it uses less digits than its factorization.

6665150561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18566238.

The product of its (nonzero) digits is 162000, while the sum is 41.

The square root of 6665150561 is about 81640.3733516696. The cubic root of 6665150561 is about 1881.9293759399.

The spelling of 6665150561 in words is "six billion, six hundred sixty-five million, one hundred fifty thousand, five hundred sixty-one".