21106513236 has 24 divisors (see below), whose sum is σ = 49262592960. Its totient is φ = 7033495552.

The previous prime is 21106513189. The next prime is 21106513237. The reversal of 21106513236 is 63231560112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21106513237) 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 in 7 ways as a sum of consecutive naturals, for example, 207021 + ... + 291668.

It is an arithmetic number, because the mean of its divisors is an integer number (2052608040).

Almost surely, 2^21106513236 is an apocalyptic number.

It is an amenable number.

21106513236 is an abundant number, since it is smaller than the sum of its proper divisors (28156079724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21106513236 is a wasteful number, since it uses less digits than its factorization.

21106513236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502223 (or 502221 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The spelling of 21106513236 in words is "twenty-one billion, one hundred six million, five hundred thirteen thousand, two hundred thirty-six".