21264981829 has 24 divisors (see below), whose sum is σ = 26777831640. Its totient is φ = 16737767424.

The previous prime is 21264981827. The next prime is 21264981847. The reversal of 21264981829 is 92818946212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1488184929 + 19776796900 = 38577^2 + 140630^2 .

It is not a de Polignac number, because 21264981829 - 2¹ = 21264981827 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264981827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36457 + ... + 209425.

It is an arithmetic number, because the mean of its divisors is an integer number (1115742985).

Almost surely, 2^21264981829 is an apocalyptic number.

It is an amenable number.

21264981829 is a deficient number, since it is larger than the sum of its proper divisors (5512849811).

21264981829 is a wasteful number, since it uses less digits than its factorization.

21264981829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173189 (or 173182 counting only the distinct ones).

The product of its digits is 995328, while the sum is 52.

The spelling of 21264981829 in words is "twenty-one billion, two hundred sixty-four million, nine hundred eighty-one thousand, eight hundred twenty-nine".