20205641 has 4 divisors (see below), whose sum is σ = 20220432. Its totient is φ = 20190852.

The previous prime is 20205623. The next prime is 20205697. The reversal of 20205641 is 14650202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20205641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20205611) 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, 5111 + ... + 8156.

It is an arithmetic number, because the mean of its divisors is an integer number (5055108).

Almost surely, 2^20205641 is an apocalyptic number.

It is an amenable number.

20205641 is a deficient number, since it is larger than the sum of its proper divisors (14791).

20205641 is a wasteful number, since it uses less digits than its factorization.

20205641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14790.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20205641 is about 4495.0685200562. The cubic root of 20205641 is about 272.3689171187.

Adding to 20205641 its reverse (14650202), we get a palindrome (34855843).

The spelling of 20205641 in words is "twenty million, two hundred five thousand, six hundred forty-one".