20421051241 has 4 divisors (see below), whose sum is σ = 20422784512. Its totient is φ = 20419317972.

The previous prime is 20421051227. The next prime is 20421051247. The reversal of 20421051241 is 14215012402.

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-20421051241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20421051247) 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, 848841 + ... + 872566.

It is an arithmetic number, because the mean of its divisors is an integer number (5105696128).

Almost surely, 2^20421051241 is an apocalyptic number.

It is an amenable number.

20421051241 is a deficient number, since it is larger than the sum of its proper divisors (1733271).

20421051241 is a wasteful number, since it uses less digits than its factorization.

20421051241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1733270.

The product of its (nonzero) digits is 640, while the sum is 22.

Adding to 20421051241 its reverse (14215012402), we get a palindrome (34636063643).

The spelling of 20421051241 in words is "twenty billion, four hundred twenty-one million, fifty-one thousand, two hundred forty-one".