21095918929 has 2 divisors, whose sum is σ = 21095918930. Its totient is φ = 21095918928.

The previous prime is 21095918923. The next prime is 21095918959. The reversal of 21095918929 is 92981959012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18729291025 + 2366627904 = 136855^2 + 48648^2 .

It is a cyclic number.

It is not a de Polignac number, because 21095918929 - 2⁵ = 21095918897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21095918929.

It is not a weakly prime, because it can be changed into another prime (21095918923) 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, 10547959464 + 10547959465.

It is an arithmetic number, because the mean of its divisors is an integer number (10547959465).

Almost surely, 2^21095918929 is an apocalyptic number.

It is an amenable number.

21095918929 is a deficient number, since it is larger than the sum of its proper divisors (1).

21095918929 is an equidigital number, since it uses as much as digits as its factorization.

21095918929 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1049760, while the sum is 55.

The spelling of 21095918929 in words is "twenty-one billion, ninety-five million, nine hundred eighteen thousand, nine hundred twenty-nine".