21229478026777 has 2 divisors, whose sum is σ = 21229478026778. Its totient is φ = 21229478026776.

The previous prime is 21229478026753. The next prime is 21229478026781. The reversal of 21229478026777 is 77762087492212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16070124667536 + 5159353359241 = 4008756^2 + 2271421^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21229478026777 is a prime.

It is not a weakly prime, because it can be changed into another prime (21229478026177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10614739013388 + 10614739013389.

It is an arithmetic number, because the mean of its divisors is an integer number (10614739013389).

Almost surely, 2^{21229478026777} is an apocalyptic number.

It is an amenable number.

21229478026777 is a deficient number, since it is larger than the sum of its proper divisors (1).

21229478026777 is an equidigital number, since it uses as much as digits as its factorization.

21229478026777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 66382848, while the sum is 64.

The spelling of 21229478026777 in words is "twenty-one trillion, two hundred twenty-nine billion, four hundred seventy-eight million, twenty-six thousand, seven hundred seventy-seven".