66663923 has 4 divisors (see below), whose sum is σ = 67793880. Its totient is φ = 65533968.

The previous prime is 66663901. The next prime is 66663931. The reversal of 66663923 is 32936666.

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

It is a cyclic number.

It is not a de Polignac number, because 66663923 - 2¹⁶ = 66598387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66666923) 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, 564890 + ... + 565007.

It is an arithmetic number, because the mean of its divisors is an integer number (16948470).

Almost surely, 2^66663923 is an apocalyptic number.

66663923 is a deficient number, since it is larger than the sum of its proper divisors (1129957).

66663923 is a wasteful number, since it uses less digits than its factorization.

66663923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1129956.

The product of its digits is 209952, while the sum is 41.

The square root of 66663923 is about 8164.7977929646. The cubic root of 66663923 is about 405.4745704503.

The spelling of 66663923 in words is "sixty-six million, six hundred sixty-three thousand, nine hundred twenty-three".