20203643 has 2 divisors, whose sum is σ = 20203644. Its totient is φ = 20203642.

The previous prime is 20203639. The next prime is 20203657. The reversal of 20203643 is 34630202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20203643 - 2² = 20203639 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20203243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10101821 + 10101822.

It is an arithmetic number, because the mean of its divisors is an integer number (10101822).

Almost surely, 2^20203643 is an apocalyptic number.

20203643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20203643 is an equidigital number, since it uses as much as digits as its factorization.

20203643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 20203643 is about 4494.8462710086. The cubic root of 20203643 is about 272.3599392457.

Adding to 20203643 its reverse (34630202), we get a palindrome (54833845).

The spelling of 20203643 in words is "twenty million, two hundred three thousand, six hundred forty-three".