20643631103 has 4 divisors (see below), whose sum is σ = 20681789928. Its totient is φ = 20605472280.

The previous prime is 20643631061. The next prime is 20643631111. The reversal of 20643631103 is 30113634602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30113634602 = 2 ⋅15056817301.

It is a cyclic number.

It is not a de Polignac number, because 20643631103 - 2²² = 20639436799 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 (20643631133) 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, 19078601 + ... + 19079682.

It is an arithmetic number, because the mean of its divisors is an integer number (5170447482).

Almost surely, 2^20643631103 is an apocalyptic number.

20643631103 is a deficient number, since it is larger than the sum of its proper divisors (38158825).

20643631103 is an equidigital number, since it uses as much as digits as its factorization.

20643631103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38158824.

The product of its (nonzero) digits is 7776, while the sum is 29.

The spelling of 20643631103 in words is "twenty billion, six hundred forty-three million, six hundred thirty-one thousand, one hundred three".