21073167556 has 27 divisors (see below), whose sum is σ = 42903085869. Its totient is φ = 9030486528.

The previous prime is 21073167503. The next prime is 21073167589. The reversal of 21073167556 is 65576137012.

The square root of 21073167556 is 145166.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1158313156 + 19914854400 = 34034^2 + 141120^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2027140 + ... + 2037508.

Almost surely, 2^21073167556 is an apocalyptic number.

21073167556 is the 145166-th square number.

It is an amenable number.

21073167556 is an abundant number, since it is smaller than the sum of its proper divisors (21829918313).

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

21073167556 is an frugal number, since it uses more digits than its factorization.

21073167556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20756 (or 10378 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 43.

The spelling of 21073167556 in words is "twenty-one billion, seventy-three million, one hundred sixty-seven thousand, five hundred fifty-six".