21271035556 has 24 divisors (see below), whose sum is σ = 37346400000. Its totient is φ = 10600687104.

The previous prime is 21271035551. The next prime is 21271035607. The reversal of 21271035556 is 65553017212.

It is not an unprimeable number, because it can be changed into a prime (21271035551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1860345 + ... + 1871743.

It is an arithmetic number, because the mean of its divisors is an integer number (1556100000).

Almost surely, 2^21271035556 is an apocalyptic number.

It is an amenable number.

21271035556 is a deficient number, since it is larger than the sum of its proper divisors (16075364444).

21271035556 is a wasteful number, since it uses less digits than its factorization.

21271035556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12891 (or 12889 counting only the distinct ones).

The product of its (nonzero) digits is 63000, while the sum is 37.

The spelling of 21271035556 in words is "twenty-one billion, two hundred seventy-one million, thirty-five thousand, five hundred fifty-six".