665555544 has 48 divisors (see below), whose sum is σ = 1812021120. Its totient is φ = 220685760.

The previous prime is 665555537. The next prime is 665555551. The reversal of 665555544 is 445555566.

665555544 is a `hidden beast` number, since 6 + 6 + 55 + 55 + 544 = 666.

665555544 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (665555537) and next prime (665555551).

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 665555544.

It is a congruent number.

It is an unprimeable number.

It is an upside-down number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10447 + ... + 37950.

It is an arithmetic number, because the mean of its divisors is an integer number (37750440).

Almost surely, 2^665555544 is an apocalyptic number.

It is an amenable number.

665555544 is an abundant number, since it is smaller than the sum of its proper divisors (1146465576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665555544 is a wasteful number, since it uses less digits than its factorization.

665555544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48600 (or 48593 counting only the distinct ones).

The product of its digits is 1800000, while the sum is 45.

The square root of 665555544 is about 25798.3632038934. The cubic root of 665555544 is about 873.0948673294.

The spelling of 665555544 in words is "six hundred sixty-five million, five hundred fifty-five thousand, five hundred forty-four".