20613256 has 16 divisors (see below), whose sum is σ = 38911500. Its totient is φ = 10236864.

The previous prime is 20613253. The next prime is 20613269. The reversal of 20613256 is 65231602.

It can be written as a sum of positive squares in 2 ways, for example, as 15729156 + 4884100 = 3966^2 + 2210^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20613256.

It is not an unprimeable number, because it can be changed into a prime (20613253) 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, 7455 + ... + 9838.

Almost surely, 2^20613256 is an apocalyptic number.

It is an amenable number.

20613256 is a deficient number, since it is larger than the sum of its proper divisors (18298244).

20613256 is a wasteful number, since it uses less digits than its factorization.

20613256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17448 (or 17444 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 20613256 is about 4540.1823751916. The cubic root of 20613256 is about 274.1882663708.

Adding to 20613256 its reverse (65231602), we get a palindrome (85844858).

It can be divided in two parts, 2061 and 3256, that multiplied together give a triangular number (6710616 = T₃₆₆₃).

The spelling of 20613256 in words is "twenty million, six hundred thirteen thousand, two hundred fifty-six".