66444621 has 8 divisors (see below), whose sum is σ = 89088480. Its totient is φ = 44048592.

The previous prime is 66444611. The next prime is 66444643. The reversal of 66444621 is 12644466.

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

It is not a de Polignac number, because 66444621 - 2¹¹ = 66442573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66444611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61330 + ... + 62403.

It is an arithmetic number, because the mean of its divisors is an integer number (11136060).

Almost surely, 2^66444621 is an apocalyptic number.

It is an amenable number.

66444621 is a deficient number, since it is larger than the sum of its proper divisors (22643859).

66444621 is a wasteful number, since it uses less digits than its factorization.

66444621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123915.

The product of its digits is 27648, while the sum is 33.

The square root of 66444621 is about 8151.3570035915. The cubic root of 66444621 is about 405.0294567814.

The spelling of 66444621 in words is "sixty-six million, four hundred forty-four thousand, six hundred twenty-one".