20889643 has 2 divisors, whose sum is σ = 20889644. Its totient is φ = 20889642.

The previous prime is 20889613. The next prime is 20889679. The reversal of 20889643 is 34698802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20889643 - 2¹³ = 20881451 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20889596 and 20889605.

It is not a weakly prime, because it can be changed into another prime (20889613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10444821 + 10444822.

It is an arithmetic number, because the mean of its divisors is an integer number (10444822).

Almost surely, 2^20889643 is an apocalyptic number.

20889643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20889643 is an equidigital number, since it uses as much as digits as its factorization.

20889643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 20889643 is about 4570.5188983309. The cubic root of 20889643 is about 275.4082882865.

The spelling of 20889643 in words is "twenty million, eight hundred eighty-nine thousand, six hundred forty-three".