21521680638284 has 12 divisors (see below), whose sum is σ = 37737817743024. Its totient is φ = 10739446997424.

The previous prime is 21521680638277. The next prime is 21521680638301. The reversal of 21521680638284 is 48283608612512.

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 3 ways as a sum of consecutive naturals, for example, 5348328167 + ... + 5348332190.

It is an arithmetic number, because the mean of its divisors is an integer number (3144818145252).

Almost surely, 2^{21521680638284} is an apocalyptic number.

It is an amenable number.

21521680638284 is a deficient number, since it is larger than the sum of its proper divisors (16216137104740).

21521680638284 is a wasteful number, since it uses less digits than its factorization.

21521680638284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10696660864 (or 10696660862 counting only the distinct ones).

The product of its (nonzero) digits is 8847360, while the sum is 56.

The spelling of 21521680638284 in words is "twenty-one trillion, five hundred twenty-one billion, six hundred eighty million, six hundred thirty-eight thousand, two hundred eighty-four".