820043923 has 4 divisors (see below), whose sum is σ = 833487328. Its totient is φ = 806600520.

The previous prime is 820043897. The next prime is 820043957. The reversal of 820043923 is 329340028.

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-820043923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820043963) 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, 6721611 + ... + 6721732.

It is an arithmetic number, because the mean of its divisors is an integer number (208371832).

Almost surely, 2^820043923 is an apocalyptic number.

820043923 is a deficient number, since it is larger than the sum of its proper divisors (13443405).

820043923 is a wasteful number, since it uses less digits than its factorization.

820043923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13443404.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 820043923 is about 28636.4090451299. The cubic root of 820043923 is about 936.0068740059.

The spelling of 820043923 in words is "eight hundred twenty million, forty-three thousand, nine hundred twenty-three".