66444646 has 8 divisors (see below), whose sum is σ = 100598760. Its totient is φ = 32911728.

The previous prime is 66444643. The next prime is 66444647. The reversal of 66444646 is 64644466.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 66444599 and 66444608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66444643) 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, 155031 + ... + 155458.

It is an arithmetic number, because the mean of its divisors is an integer number (12574845).

Almost surely, 2^66444646 is an apocalyptic number.

66444646 is a deficient number, since it is larger than the sum of its proper divisors (34154114).

66444646 is a wasteful number, since it uses less digits than its factorization.

66444646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310598.

The product of its digits is 331776, while the sum is 40.

The square root of 66444646 is about 8151.3585370783. The cubic root of 66444646 is about 405.0295075793.

The spelling of 66444646 in words is "sixty-six million, four hundred forty-four thousand, six hundred forty-six".