21255427601 has 2 divisors, whose sum is σ = 21255427602. Its totient is φ = 21255427600.

The previous prime is 21255427597. The next prime is 21255427603. The reversal of 21255427601 is 10672455212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21221496976 + 33930625 = 145676^2 + 5825^2 .

It is a cyclic number.

It is not a de Polignac number, because 21255427601 - 2² = 21255427597 is a prime.

Together with 21255427603, 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 (21255427603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627713800 + 10627713801.

It is an arithmetic number, because the mean of its divisors is an integer number (10627713801).

Almost surely, 2^21255427601 is an apocalyptic number.

It is an amenable number.

21255427601 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255427601 is an equidigital number, since it uses as much as digits as its factorization.

21255427601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 33600, while the sum is 35.

The spelling of 21255427601 in words is "twenty-one billion, two hundred fifty-five million, four hundred twenty-seven thousand, six hundred one".