21135527156 has 6 divisors (see below), whose sum is σ = 36987172530. Its totient is φ = 10567763576.

The previous prime is 21135527113. The next prime is 21135527159. The reversal of 21135527156 is 65172553112.

It can be written as a sum of positive squares in only one way, i.e., 20738880100 + 396647056 = 144010^2 + 19916^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21135527159) 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, 2641940891 + ... + 2641940898.

It is an arithmetic number, because the mean of its divisors is an integer number (6164528755).

Almost surely, 2^21135527156 is an apocalyptic number.

It is an amenable number.

21135527156 is a deficient number, since it is larger than the sum of its proper divisors (15851645374).

21135527156 is a wasteful number, since it uses less digits than its factorization.

21135527156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5283881793 (or 5283881791 counting only the distinct ones).

The product of its digits is 63000, while the sum is 38.

The spelling of 21135527156 in words is "twenty-one billion, one hundred thirty-five million, five hundred twenty-seven thousand, one hundred fifty-six".