20451642143 has 4 divisors (see below), whose sum is σ = 20457829800. Its totient is φ = 20445454488.

The previous prime is 20451642139. The next prime is 20451642187. The reversal of 20451642143 is 34124615402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20451642143 - 2² = 20451642139 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20451642443) 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, 3088868 + ... + 3095481.

It is an arithmetic number, because the mean of its divisors is an integer number (5114457450).

Almost surely, 2^20451642143 is an apocalyptic number.

20451642143 is a deficient number, since it is larger than the sum of its proper divisors (6187657).

20451642143 is an equidigital number, since it uses as much as digits as its factorization.

20451642143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6187656.

The product of its (nonzero) digits is 23040, while the sum is 32.

The spelling of 20451642143 in words is "twenty billion, four hundred fifty-one million, six hundred forty-two thousand, one hundred forty-three".