21012950887 has 2 divisors, whose sum is σ = 21012950888. Its totient is φ = 21012950886.

The previous prime is 21012950879. The next prime is 21012950891. The reversal of 21012950887 is 78805921012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21012950887 - 2³ = 21012950879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012650887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506475443 + 10506475444.

It is an arithmetic number, because the mean of its divisors is an integer number (10506475444).

Almost surely, 2^21012950887 is an apocalyptic number.

21012950887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012950887 is an equidigital number, since it uses as much as digits as its factorization.

21012950887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 43.

The spelling of 21012950887 in words is "twenty-one billion, twelve million, nine hundred fifty thousand, eight hundred eighty-seven".