21011222220077 has 2 divisors, whose sum is σ = 21011222220078. Its totient is φ = 21011222220076.

The previous prime is 21011222220041. The next prime is 21011222220103. The reversal of 21011222220077 is 77002222211012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20976665640841 + 34556579236 = 4580029^2 + 185894^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011222220077 - 2⁸ = 21011222219821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011222220017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505611110038 + 10505611110039.

It is an arithmetic number, because the mean of its divisors is an integer number (10505611110039).

Almost surely, 2^{21011222220077} is an apocalyptic number.

It is an amenable number.

21011222220077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011222220077 is an equidigital number, since it uses as much as digits as its factorization.

21011222220077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3136, while the sum is 29.

Adding to 21011222220077 its reverse (77002222211012), we get a palindrome (98013444431089).

The spelling of 21011222220077 in words is "twenty-one trillion, eleven billion, two hundred twenty-two million, two hundred twenty thousand, seventy-seven".