21222111077 has 2 divisors, whose sum is σ = 21222111078. Its totient is φ = 21222111076.

The previous prime is 21222111049. The next prime is 21222111137. The reversal of 21222111077 is 77011122212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11406453601 + 9815657476 = 106801^2 + 99074^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222111077 - 2⁶ = 21222111013 is a prime.

It is a super-3 number, since 3×21222111077³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222111577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611055538 + 10611055539.

It is an arithmetic number, because the mean of its divisors is an integer number (10611055539).

Almost surely, 2^21222111077 is an apocalyptic number.

It is an amenable number.

21222111077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222111077 is an equidigital number, since it uses as much as digits as its factorization.

21222111077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 784, while the sum is 26.

Adding to 21222111077 its reverse (77011122212), we get a palindrome (98233233289).

The spelling of 21222111077 in words is "twenty-one billion, two hundred twenty-two million, one hundred eleven thousand, seventy-seven".