20345643 has 6 divisors (see below), whose sum is σ = 29388164. Its totient is φ = 13563756.

The previous prime is 20345629. The next prime is 20345659. The reversal of 20345643 is 34654302.

20345643 is a `hidden beast` number, since 203 + 456 + 4 + 3 = 666.

It is not a de Polignac number, because 20345643 - 2¹⁰ = 20344619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20345603) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1130305 + ... + 1130322.

Almost surely, 2^20345643 is an apocalyptic number.

20345643 is a deficient number, since it is larger than the sum of its proper divisors (9042521).

20345643 is a wasteful number, since it uses less digits than its factorization.

20345643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2260633 (or 2260630 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 27.

The square root of 20345643 is about 4510.6144814205. The cubic root of 20345643 is about 272.9965382164.

Adding to 20345643 its reverse (34654302), we get a palindrome (54999945).

The spelling of 20345643 in words is "twenty million, three hundred forty-five thousand, six hundred forty-three".