20649256 has 16 divisors (see below), whose sum is σ = 39764340. Its totient is φ = 10045440.

The previous prime is 20649253. The next prime is 20649259. The reversal of 20649256 is 65294602.

It is an interprime number because it is at equal distance from previous prime (20649253) and next prime (20649259).

It can be written as a sum of positive squares in 2 ways, for example, as 17926756 + 2722500 = 4234^2 + 1650^2 .

It is not an unprimeable number, because it can be changed into a prime (20649253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34585 + ... + 35176.

Almost surely, 2^20649256 is an apocalyptic number.

It is an amenable number.

20649256 is a deficient number, since it is larger than the sum of its proper divisors (19115084).

20649256 is a wasteful number, since it uses less digits than its factorization.

20649256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69804 (or 69800 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 20649256 is about 4544.1452441576. The cubic root of 20649256 is about 274.3477921454.

The spelling of 20649256 in words is "twenty million, six hundred forty-nine thousand, two hundred fifty-six".