20889457 has 4 divisors (see below), whose sum is σ = 21124260. Its totient is φ = 20654656.

The previous prime is 20889439. The next prime is 20889467. The reversal of 20889457 is 75498802.

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 5239521 + 15649936 = 2289^2 + 3956^2 .

It is a cyclic number.

It is not a de Polignac number, because 20889457 - 2²³ = 12500849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20889437) 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, 117268 + ... + 117445.

It is an arithmetic number, because the mean of its divisors is an integer number (5281065).

Almost surely, 2^20889457 is an apocalyptic number.

It is an amenable number.

20889457 is a deficient number, since it is larger than the sum of its proper divisors (234803).

20889457 is an equidigital number, since it uses as much as digits as its factorization.

20889457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234802.

The product of its (nonzero) digits is 161280, while the sum is 43.

The square root of 20889457 is about 4570.4985504866. The cubic root of 20889457 is about 275.4074708783.

The spelling of 20889457 in words is "twenty million, eight hundred eighty-nine thousand, four hundred fifty-seven".