20982609 has 24 divisors (see below), whose sum is σ = 31111080. Its totient is φ = 13623552.

The previous prime is 20982569. The next prime is 20982613. The reversal of 20982609 is 90628902.

It can be written as a sum of positive squares in 4 ways, for example, as 10870209 + 10112400 = 3297^2 + 3180^2 .

It is not a de Polignac number, because 20982609 - 2¹⁶ = 20917073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20982659) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71467 + ... + 71759.

It is an arithmetic number, because the mean of its divisors is an integer number (1296295).

Almost surely, 2^20982609 is an apocalyptic number.

It is an amenable number.

20982609 is a deficient number, since it is larger than the sum of its proper divisors (10128471).

20982609 is a wasteful number, since it uses less digits than its factorization.

20982609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481 (or 478 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 20982609 is about 4580.6777882754. The cubic root of 20982609 is about 275.8162371598.

The spelling of 20982609 in words is "twenty million, nine hundred eighty-two thousand, six hundred nine".