20943001 has 4 divisors (see below), whose sum is σ = 20957904. Its totient is φ = 20928100.

The previous prime is 20942951. The next prime is 20943007. The reversal of 20943001 is 10034902.

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, and also an emirpimes, since its reverse is a distinct semiprime: 10034902 = 2 ⋅5017451.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20943001 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20943001.

It is not an unprimeable number, because it can be changed into a prime (20943007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5095 + ... + 8236.

It is an arithmetic number, because the mean of its divisors is an integer number (5239476).

Almost surely, 2^20943001 is an apocalyptic number.

It is an amenable number.

20943001 is a deficient number, since it is larger than the sum of its proper divisors (14903).

20943001 is a wasteful number, since it uses less digits than its factorization.

20943001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14902.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 20943001 is about 4576.3523684262. The cubic root of 20943001 is about 275.6425788909.

Adding to 20943001 its reverse (10034902), we get a palindrome (30977903).

The spelling of 20943001 in words is "twenty million, nine hundred forty-three thousand, one".