21658733923 has 4 divisors (see below), whose sum is σ = 22186995768. Its totient is φ = 21130472080.

The previous prime is 21658733869. The next prime is 21658733939. The reversal of 21658733923 is 32933785612.

It is a happy number.

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 21658733923 - 2¹⁷ = 21658602851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21658733953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264130861 + ... + 264130942.

It is an arithmetic number, because the mean of its divisors is an integer number (5546748942).

Almost surely, 2^21658733923 is an apocalyptic number.

21658733923 is a deficient number, since it is larger than the sum of its proper divisors (528261845).

21658733923 is an equidigital number, since it uses as much as digits as its factorization.

21658733923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528261844.

The product of its digits is 1632960, while the sum is 49.

The spelling of 21658733923 in words is "twenty-one billion, six hundred fifty-eight million, seven hundred thirty-three thousand, nine hundred twenty-three".