20356721323 has 4 divisors (see below), whose sum is σ = 20690438128. Its totient is φ = 20023004520.

The previous prime is 20356721321. The next prime is 20356721327. The reversal of 20356721323 is 32312765302.

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 20356721323 - 2¹ = 20356721321 is a prime.

It is a super-2 number, since 2×20356721323² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20356721321) 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, 166858311 + ... + 166858432.

It is an arithmetic number, because the mean of its divisors is an integer number (5172609532).

Almost surely, 2^20356721323 is an apocalyptic number.

20356721323 is a deficient number, since it is larger than the sum of its proper divisors (333716805).

20356721323 is an equidigital number, since it uses as much as digits as its factorization.

20356721323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333716804.

The product of its (nonzero) digits is 45360, while the sum is 34.

The spelling of 20356721323 in words is "twenty billion, three hundred fifty-six million, seven hundred twenty-one thousand, three hundred twenty-three".