21220022077 has 2 divisors, whose sum is σ = 21220022078. Its totient is φ = 21220022076.

The previous prime is 21220022063. The next prime is 21220022119. The reversal of 21220022077 is 77022002212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11317980996 + 9902041081 = 106386^2 + 99509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220022077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220022977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610011038 + 10610011039.

It is an arithmetic number, because the mean of its divisors is an integer number (10610011039).

Almost surely, 2^21220022077 is an apocalyptic number.

It is an amenable number.

21220022077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220022077 is an equidigital number, since it uses as much as digits as its factorization.

21220022077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1568, while the sum is 25.

Adding to 21220022077 its reverse (77022002212), we get a palindrome (98242024289).

The spelling of 21220022077 in words is "twenty-one billion, two hundred twenty million, twenty-two thousand, seventy-seven".