20005556481 has 9 divisors (see below), whose sum is σ = 28897527841. Its totient is φ = 13336754772.

The previous prime is 20005556447. The next prime is 20005556489. The reversal of 20005556481 is 18465550002.

The square root of 20005556481 is 141441.

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

20005556481 is a `hidden beast` number, since 2 + 0 + 0 + 0 + 5 + 5 + 5 + 648 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 20005556481 - 2¹¹ = 20005554433 is a prime.

It is a super-2 number, since 2×20005556481² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20005556489) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 400750 + ... + 447896.

Almost surely, 2^20005556481 is an apocalyptic number.

20005556481 is the 141441-st square number.

20005556481 is the 70721-st centered octagonal number.

It is an amenable number.

20005556481 is a deficient number, since it is larger than the sum of its proper divisors (8891971360).

20005556481 is an frugal number, since it uses more digits than its factorization.

20005556481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94300 (or 47150 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 36.

Multiplying 20005556481 by its sum of digits (36), we get a square (720200033316 = 848646²).

The spelling of 20005556481 in words is "twenty billion, five million, five hundred fifty-six thousand, four hundred eighty-one".