21101875643 has 2 divisors, whose sum is σ = 21101875644. Its totient is φ = 21101875642.

The previous prime is 21101875609. The next prime is 21101875649. The reversal of 21101875643 is 34657810112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101875643 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21101875597 and 21101875606.

It is not a weakly prime, because it can be changed into another prime (21101875649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550937821 + 10550937822.

It is an arithmetic number, because the mean of its divisors is an integer number (10550937822).

Almost surely, 2^21101875643 is an apocalyptic number.

21101875643 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101875643 is an equidigital number, since it uses as much as digits as its factorization.

21101875643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 38.

The spelling of 21101875643 in words is "twenty-one billion, one hundred one million, eight hundred seventy-five thousand, six hundred forty-three".