21775654427 has 2 divisors, whose sum is σ = 21775654428. Its totient is φ = 21775654426.

The previous prime is 21775654391. The next prime is 21775654429. The reversal of 21775654427 is 72445657712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21775654427 - 2³⁰ = 20701912603 is a prime.

Together with 21775654429, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21775654429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10887827213 + 10887827214.

It is an arithmetic number, because the mean of its divisors is an integer number (10887827214).

Almost surely, 2^21775654427 is an apocalyptic number.

21775654427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21775654427 is an equidigital number, since it uses as much as digits as its factorization.

21775654427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3292800, while the sum is 50.

The spelling of 21775654427 in words is "twenty-one billion, seven hundred seventy-five million, six hundred fifty-four thousand, four hundred twenty-seven".