21306535828 has 24 divisors (see below), whose sum is σ = 38579698080. Its totient is φ = 10283908320.

The previous prime is 21306535807. The next prime is 21306535843. The reversal of 21306535828 is 82853560312.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 704743 + ... + 734353.

It is an arithmetic number, because the mean of its divisors is an integer number (1607487420).

Almost surely, 2^21306535828 is an apocalyptic number.

It is an amenable number.

21306535828 is a deficient number, since it is larger than the sum of its proper divisors (17273162252).

21306535828 is a wasteful number, since it uses less digits than its factorization.

21306535828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35847 (or 35845 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 43.

The spelling of 21306535828 in words is "twenty-one billion, three hundred six million, five hundred thirty-five thousand, eight hundred twenty-eight".