20623643 has 2 divisors, whose sum is σ = 20623644. Its totient is φ = 20623642.

The previous prime is 20623621. The next prime is 20623693. The reversal of 20623643 is 34632602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20623643 - 2⁶ = 20623579 is a prime.

It is not a weakly prime, because it can be changed into another prime (20623693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10311821 + 10311822.

It is an arithmetic number, because the mean of its divisors is an integer number (10311822).

Almost surely, 2^20623643 is an apocalyptic number.

20623643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20623643 is an equidigital number, since it uses as much as digits as its factorization.

20623643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 26.

The square root of 20623643 is about 4541.3261279058. The cubic root of 20623643 is about 274.2343130392.

The spelling of 20623643 in words is "twenty million, six hundred twenty-three thousand, six hundred forty-three".