20643452051 has 4 divisors (see below), whose sum is σ = 20643752352. Its totient is φ = 20643151752.

The previous prime is 20643452047. The next prime is 20643452059. The reversal of 20643452051 is 15025434602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20643452051 - 2² = 20643452047 is a prime.

It is a super-2 number, since 2×20643452051² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20643451999 and 20643452017.

It is not an unprimeable number, because it can be changed into a prime (20643452059) 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, 9665 + ... + 203421.

It is an arithmetic number, because the mean of its divisors is an integer number (5160938088).

Almost surely, 2^20643452051 is an apocalyptic number.

20643452051 is a deficient number, since it is larger than the sum of its proper divisors (300301).

20643452051 is a wasteful number, since it uses less digits than its factorization.

20643452051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300300.

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 20643452051 its reverse (15025434602), we get a palindrome (35668886653).

The spelling of 20643452051 in words is "twenty billion, six hundred forty-three million, four hundred fifty-two thousand, fifty-one".