21102242977 has 2 divisors, whose sum is σ = 21102242978. Its totient is φ = 21102242976.

The previous prime is 21102242947. The next prime is 21102243007. The reversal of 21102242977 is 77924220112.

It is a balanced prime because it is at equal distance from previous prime (21102242947) and next prime (21102243007).

It can be written as a sum of positive squares in only one way, i.e., 10651065616 + 10451177361 = 103204^2 + 102231^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102242977 - 2¹⁹ = 21101718689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21102242927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551121488 + 10551121489.

It is an arithmetic number, because the mean of its divisors is an integer number (10551121489).

Almost surely, 2^21102242977 is an apocalyptic number.

It is an amenable number.

21102242977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102242977 is an equidigital number, since it uses as much as digits as its factorization.

21102242977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 37.

The spelling of 21102242977 in words is "twenty-one billion, one hundred two million, two hundred forty-two thousand, nine hundred seventy-seven".