20657545 has 16 divisors (see below), whose sum is σ = 25485840. Its totient is φ = 16067584.

The previous prime is 20657543. The next prime is 20657557. The reversal of 20657545 is 54575602.

It can be written as a sum of positive squares in 8 ways, for example, as 190969 + 20466576 = 437^2 + 4524^2 .

It is a cyclic number.

It is not a de Polignac number, because 20657545 - 2¹ = 20657543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20657545.

It is not an unprimeable number, because it can be changed into a prime (20657543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36021 + ... + 36589.

It is an arithmetic number, because the mean of its divisors is an integer number (1592865).

Almost surely, 2^20657545 is an apocalyptic number.

It is an amenable number.

20657545 is a deficient number, since it is larger than the sum of its proper divisors (4828295).

20657545 is a wasteful number, since it uses less digits than its factorization.

20657545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764.

The product of its (nonzero) digits is 42000, while the sum is 34.

The square root of 20657545 is about 4545.0572053606. The cubic root of 20657545 is about 274.3844966903.

The spelling of 20657545 in words is "twenty million, six hundred fifty-seven thousand, five hundred forty-five".