20045561609529 has 27 divisors (see below), whose sum is σ = 29013586082949. Its totient is φ = 13336584698520.

The previous prime is 20045561609473. The next prime is 20045561609537. The reversal of 20045561609529 is 92590616554002.

The square root of 20045561609529 is 4477227.

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

20045561609529 is a `hidden beast` number, since 2 + 0 + 0 + 4 + 5 + 5 + 6 + 1 + 609 + 5 + 29 = 666.

It is not a de Polignac number, because 20045561609529 - 2⁷ = 20045561609401 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (20045561609329) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 8314209334 + ... + 8314211744.

Almost surely, 2^{20045561609529} is an apocalyptic number.

20045561609529 is the 4477227-th square number.

20045561609529 is the 2238614-th centered octagonal number.

It is an amenable number.

20045561609529 is a deficient number, since it is larger than the sum of its proper divisors (8968024473420).

20045561609529 is an frugal number, since it uses more digits than its factorization.

20045561609529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6066 (or 3033 counting only the distinct ones).

The product of its (nonzero) digits is 5832000, while the sum is 54.

The spelling of 20045561609529 in words is "twenty trillion, forty-five billion, five hundred sixty-one million, six hundred nine thousand, five hundred twenty-nine".