21111530356 has 48 divisors (see below), whose sum is σ = 42939388800. Its totient is φ = 8894844288.

The previous prime is 21111530261. The next prime is 21111530383. The reversal of 21111530356 is 65303511112.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 943830 + ... + 965938.

It is an arithmetic number, because the mean of its divisors is an integer number (894570600).

Almost surely, 2^21111530356 is an apocalyptic number.

It is an amenable number.

21111530356 is an abundant number, since it is smaller than the sum of its proper divisors (21827858444).

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

21111530356 is a wasteful number, since it uses less digits than its factorization.

21111530356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22696 (or 22694 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 28.

The spelling of 21111530356 in words is "twenty-one billion, one hundred eleven million, five hundred thirty thousand, three hundred fifty-six".