20623045021 has 4 divisors (see below), whose sum is σ = 21012159132. Its totient is φ = 20233930912.

The previous prime is 20623045019. The next prime is 20623045031. The reversal of 20623045021 is 12054032602.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15159765625 + 5463279396 = 123125^2 + 73914^2 .

It is a cyclic number.

It is not a de Polignac number, because 20623045021 - 2¹ = 20623045019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20623045031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194556976 + ... + 194557081.

It is an arithmetic number, because the mean of its divisors is an integer number (5253039783).

Almost surely, 2^20623045021 is an apocalyptic number.

It is an amenable number.

20623045021 is a deficient number, since it is larger than the sum of its proper divisors (389114111).

20623045021 is an equidigital number, since it uses as much as digits as its factorization.

20623045021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389114110.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 20623045021 its reverse (12054032602), we get a palindrome (32677077623).

The spelling of 20623045021 in words is "twenty billion, six hundred twenty-three million, forty-five thousand, twenty-one".