66315623 has 24 divisors (see below), whose sum is σ = 78178464. Its totient is φ = 56010240.

The previous prime is 66315619. The next prime is 66315629. The reversal of 66315623 is 32651366.

It is not a de Polignac number, because 66315623 - 2² = 66315619 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 66315623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66315629) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 211715 + ... + 212027.

It is an arithmetic number, because the mean of its divisors is an integer number (3257436).

Almost surely, 2^66315623 is an apocalyptic number.

66315623 is a deficient number, since it is larger than the sum of its proper divisors (11862841).

66315623 is a wasteful number, since it uses less digits than its factorization.

66315623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455 (or 444 counting only the distinct ones).

The product of its digits is 19440, while the sum is 32.

The square root of 66315623 is about 8143.4404891299. The cubic root of 66315623 is about 404.7671740080.

Adding to 66315623 its reverse (32651366), we get a palindrome (98966989).

The spelling of 66315623 in words is "sixty-six million, three hundred fifteen thousand, six hundred twenty-three".