20440989 has 6 divisors (see below), whose sum is σ = 29525886. Its totient is φ = 13627320.

The previous prime is 20440961. The next prime is 20440993. The reversal of 20440989 is 98904402.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 11168964 + 9272025 = 3342^2 + 3045^2 .

It is not a de Polignac number, because 20440989 - 2⁵ = 20440957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20440999) 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 5 ways as a sum of consecutive naturals, for example, 1135602 + ... + 1135619.

It is an arithmetic number, because the mean of its divisors is an integer number (4920981).

Almost surely, 2^20440989 is an apocalyptic number.

It is an amenable number.

20440989 is a deficient number, since it is larger than the sum of its proper divisors (9084897).

20440989 is a wasteful number, since it uses less digits than its factorization.

20440989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2271227 (or 2271224 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 20440989 is about 4521.1711978203. The cubic root of 20440989 is about 273.4223226340.

The spelling of 20440989 in words is "twenty million, four hundred forty thousand, nine hundred eighty-nine".