21011070077 has 2 divisors, whose sum is σ = 21011070078. Its totient is φ = 21011070076.

The previous prime is 21011070007. The next prime is 21011070079. The reversal of 21011070077 is 77007011012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21010212601 + 857476 = 144949^2 + 926^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011070077 - 2¹⁸ = 21010807933 is a prime.

Together with 21011070079, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011070079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505535038 + 10505535039.

It is an arithmetic number, because the mean of its divisors is an integer number (10505535039).

Almost surely, 2^21011070077 is an apocalyptic number.

It is an amenable number.

21011070077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011070077 is an equidigital number, since it uses as much as digits as its factorization.

21011070077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 686, while the sum is 26.

Adding to 21011070077 its reverse (77007011012), we get a palindrome (98018081089).

The spelling of 21011070077 in words is "twenty-one billion, eleven million, seventy thousand, seventy-seven".