21127686869 has 2 divisors, whose sum is σ = 21127686870. Its totient is φ = 21127686868.

The previous prime is 21127686859. The next prime is 21127686871. The reversal of 21127686869 is 96868672112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10751616100 + 10376070769 = 103690^2 + 101863^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21127686869 is a prime.

It is a super-2 number, since 2×21127686869² (a number of 21 digits) contains 22 as substring.

Together with 21127686871, 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 (21127686829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10563843434 + 10563843435.

It is an arithmetic number, because the mean of its divisors is an integer number (10563843435).

Almost surely, 2^21127686869 is an apocalyptic number.

It is an amenable number.

21127686869 is a deficient number, since it is larger than the sum of its proper divisors (1).

21127686869 is an equidigital number, since it uses as much as digits as its factorization.

21127686869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3483648, while the sum is 56.

The spelling of 21127686869 in words is "twenty-one billion, one hundred twenty-seven million, six hundred eighty-six thousand, eight hundred sixty-nine".