21721130842382 has 16 divisors (see below), whose sum is σ = 32886746910720. Its totient is φ = 10758885260088.

The previous prime is 21721130842351. The next prime is 21721130842409. The reversal of 21721130842382 is 28324803112712.

It is a happy number.

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, 12496469 + ... + 14128127.

It is an arithmetic number, because the mean of its divisors is an integer number (2055421681920).

Almost surely, 2^{21721130842382} is an apocalyptic number.

21721130842382 is a deficient number, since it is larger than the sum of its proper divisors (11165616068338).

21721130842382 is a wasteful number, since it uses less digits than its factorization.

21721130842382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1693975.

The product of its (nonzero) digits is 258048, while the sum is 44.

The spelling of 21721130842382 in words is "twenty-one trillion, seven hundred twenty-one billion, one hundred thirty million, eight hundred forty-two thousand, three hundred eighty-two".