66812923 has 4 divisors (see below), whose sum is σ = 67563720. Its totient is φ = 66062128.

The previous prime is 66812887. The next prime is 66812929. The reversal of 66812923 is 32921866.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66812923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66812929) 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, 375265 + ... + 375442.

It is an arithmetic number, because the mean of its divisors is an integer number (16890930).

Almost surely, 2^66812923 is an apocalyptic number.

66812923 is a deficient number, since it is larger than the sum of its proper divisors (750797).

66812923 is an equidigital number, since it uses as much as digits as its factorization.

66812923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750796.

The product of its digits is 31104, while the sum is 37.

The square root of 66812923 is about 8173.9172371636. The cubic root of 66812923 is about 405.7764366498.

It can be divided in two parts, 6681 and 2923, that added together give a square (9604 = 98²).

The spelling of 66812923 in words is "sixty-six million, eight hundred twelve thousand, nine hundred twenty-three".