20345663 has 4 divisors (see below), whose sum is σ = 21910728. Its totient is φ = 18780600.

The previous prime is 20345659. The next prime is 20345669. The reversal of 20345663 is 36654302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20345663 - 2² = 20345659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20345669) 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, 782513 + ... + 782538.

It is an arithmetic number, because the mean of its divisors is an integer number (5477682).

Almost surely, 2^20345663 is an apocalyptic number.

20345663 is a deficient number, since it is larger than the sum of its proper divisors (1565065).

20345663 is a wasteful number, since it uses less digits than its factorization.

20345663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1565064.

The product of its (nonzero) digits is 12960, while the sum is 29.

The square root of 20345663 is about 4510.6166984128. The cubic root of 20345663 is about 272.9966276693.

Adding to 20345663 its reverse (36654302), we get a palindrome (56999965).

The spelling of 20345663 in words is "twenty million, three hundred forty-five thousand, six hundred sixty-three".