20889511 has 4 divisors (see below), whose sum is σ = 21232024. Its totient is φ = 20547000.

The previous prime is 20889509. The next prime is 20889521. The reversal of 20889511 is 11598802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11598802 = 2 ⋅5799401.

It is a cyclic number.

It is not a de Polignac number, because 20889511 - 2¹ = 20889509 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 (20889521) 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, 171165 + ... + 171286.

It is an arithmetic number, because the mean of its divisors is an integer number (5308006).

Almost surely, 2^20889511 is an apocalyptic number.

20889511 is a deficient number, since it is larger than the sum of its proper divisors (342513).

20889511 is an equidigital number, since it uses as much as digits as its factorization.

20889511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342512.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 20889511 is about 4570.5044579346. The cubic root of 20889511 is about 275.4077081909.

The spelling of 20889511 in words is "twenty million, eight hundred eighty-nine thousand, five hundred eleven".