20989438 has 4 divisors (see below), whose sum is σ = 31484160. Its totient is φ = 10494718.

The previous prime is 20989421. The next prime is 20989439. The reversal of 20989438 is 83498902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83498902 = 2 ⋅41749451.

It is a junction number, because it is equal to n+sod(n) for n = 20989394 and 20989403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5247358 + ... + 5247361.

It is an arithmetic number, because the mean of its divisors is an integer number (7871040).

Almost surely, 2^20989438 is an apocalyptic number.

20989438 is a deficient number, since it is larger than the sum of its proper divisors (10494722).

20989438 is a wasteful number, since it uses less digits than its factorization.

20989438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10494721.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 20989438 is about 4581.4231413394. The cubic root of 20989438 is about 275.8461562987.

The spelling of 20989438 in words is "twenty million, nine hundred eighty-nine thousand, four hundred thirty-eight".