66943623 has 4 divisors (see below), whose sum is σ = 89258168. Its totient is φ = 44629080.

The previous prime is 66943621. The next prime is 66943627. The reversal of 66943623 is 32634966.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 66943623 - 2¹ = 66943621 is a prime.

It is a super-2 number, since 2×66943623² = 8962897320732258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66943621) 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, 11157268 + ... + 11157273.

It is an arithmetic number, because the mean of its divisors is an integer number (22314542).

Almost surely, 2^66943623 is an apocalyptic number.

66943623 is a deficient number, since it is larger than the sum of its proper divisors (22314545).

66943623 is a wasteful number, since it uses less digits than its factorization.

66943623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22314544.

The product of its digits is 139968, while the sum is 39.

The square root of 66943623 is about 8181.9082737464. The cubic root of 66943623 is about 406.0408587254.

The spelling of 66943623 in words is "sixty-six million, nine hundred forty-three thousand, six hundred twenty-three".