21871956671552 has 56 divisors (see below), whose sum is σ = 48004056738456. Its totient is φ = 9821918158848.

The previous prime is 21871956671527. The next prime is 21871956671569. The reversal of 21871956671552 is 25517665917812.

It can be written as a sum of positive squares in 4 ways, for example, as 291323585536 + 21580633086016 = 539744^2 + 4645496^2 .

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, 355217993 + ... + 355279560.

It is an arithmetic number, because the mean of its divisors is an integer number (857215298901).

Almost surely, 2^{21871956671552} is an apocalyptic number.

It is an amenable number.

21871956671552 is an abundant number, since it is smaller than the sum of its proper divisors (26132100066904).

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

21871956671552 is a wasteful number, since it uses less digits than its factorization.

21871956671552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710497615 (or 710497605 counting only the distinct ones).

The product of its digits is 63504000, while the sum is 65.

The spelling of 21871956671552 in words is "twenty-one trillion, eight hundred seventy-one billion, nine hundred fifty-six million, six hundred seventy-one thousand, five hundred fifty-two".