66555612 has 36 divisors (see below), whose sum is σ = 178135776. Its totient is φ = 20880000.

The previous prime is 66555607. The next prime is 66555617. The reversal of 66555612 is 21655566.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66555607) and next prime (66555617).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66555617) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53764 + ... + 54987.

It is an arithmetic number, because the mean of its divisors is an integer number (4948216).

Almost surely, 2^66555612 is an apocalyptic number.

It is an amenable number.

66555612 is an abundant number, since it is smaller than the sum of its proper divisors (111580164).

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

66555612 is a wasteful number, since it uses less digits than its factorization.

66555612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108778 (or 108773 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 66555612 is about 8158.1622930658. The cubic root of 66555612 is about 405.2548555963.

The spelling of 66555612 in words is "sixty-six million, five hundred fifty-five thousand, six hundred twelve".