20245665 has 16 divisors (see below), whose sum is σ = 35338176. Its totient is φ = 9816000.

The previous prime is 20245651. The next prime is 20245669. The reversal of 20245665 is 56654202.

It is not a de Polignac number, because 20245665 - 2⁴ = 20245649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20245669) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61186 + ... + 61515.

It is an arithmetic number, because the mean of its divisors is an integer number (2208636).

Almost surely, 2^20245665 is an apocalyptic number.

It is an amenable number.

20245665 is a deficient number, since it is larger than the sum of its proper divisors (15092511).

20245665 is a wasteful number, since it uses less digits than its factorization.

20245665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122720.

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 20245665 is about 4499.5183075525. The cubic root of 20245665 is about 272.5486376163.

Adding to 20245665 its reverse (56654202), we get a palindrome (76899867).

It can be divided in two parts, 20245 and 665, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 20245665 in words is "twenty million, two hundred forty-five thousand, six hundred sixty-five".