66405723 has 16 divisors (see below), whose sum is σ = 94381056. Its totient is φ = 41385600.

The previous prime is 66405707. The next prime is 66405749. The reversal of 66405723 is 32750466.

It is not a de Polignac number, because 66405723 - 2⁴ = 66405707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66405763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3390 + ... + 12012.

It is an arithmetic number, because the mean of its divisors is an integer number (5898816).

Almost surely, 2^66405723 is an apocalyptic number.

66405723 is a deficient number, since it is larger than the sum of its proper divisors (27975333).

66405723 is a wasteful number, since it uses less digits than its factorization.

66405723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8794.

The product of its (nonzero) digits is 30240, while the sum is 33.

The square root of 66405723 is about 8148.9706711952. The cubic root of 66405723 is about 404.9504039252.

The spelling of 66405723 in words is "sixty-six million, four hundred five thousand, seven hundred twenty-three".