6665565561407 has 4 divisors (see below), whose sum is σ = 6666839322720. Its totient is φ = 6664291800096.

The previous prime is 6665565561377. The next prime is 6665565561409. The reversal of 6665565561407 is 7041655655666.

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 6665565561407 - 2¹⁶ = 6665565495871 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6665565561407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665565561409) 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, 636872807 + ... + 636883272.

It is an arithmetic number, because the mean of its divisors is an integer number (1666709830680).

Almost surely, 2^{6665565561407} is an apocalyptic number.

6665565561407 is a deficient number, since it is larger than the sum of its proper divisors (1273761313).

6665565561407 is a wasteful number, since it uses less digits than its factorization.

6665565561407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273761312.

The product of its (nonzero) digits is 136080000, while the sum is 62.

The spelling of 6665565561407 in words is "six trillion, six hundred sixty-five billion, five hundred sixty-five million, five hundred sixty-one thousand, four hundred seven".