21522261556 has 12 divisors (see below), whose sum is σ = 37677859492. Its totient is φ = 10757158848.

The previous prime is 21522261539. The next prime is 21522261557. The reversal of 21522261556 is 65516222512.

It can be written as a sum of positive squares in 2 ways, for example, as 16137637156 + 5384624400 = 127034^2 + 73380^2 .

It is a super-2 number, since 2×21522261556² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522261557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 980775 + ... + 1002478.

Almost surely, 2^21522261556 is an apocalyptic number.

It is an amenable number.

21522261556 is a deficient number, since it is larger than the sum of its proper divisors (16155597936).

21522261556 is a wasteful number, since it uses less digits than its factorization.

21522261556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1985970 (or 1985968 counting only the distinct ones).

The product of its digits is 72000, while the sum is 37.

The spelling of 21522261556 in words is "twenty-one billion, five hundred twenty-two million, two hundred sixty-one thousand, five hundred fifty-six".