20872447729 has 9 divisors (see below), whose sum is σ = 24281370777. Its totient is φ = 17889802644.

The previous prime is 20872447711. The next prime is 20872447753. The reversal of 20872447729 is 92774427802.

The square root of 20872447729 is 144473.

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

It is not a de Polignac number, because 20872447729 - 2⁷ = 20872447601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20872447129) 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, 1000992 + ... + 1021630.

Almost surely, 2^20872447729 is an apocalyptic number.

20872447729 is the 144473-rd square number.

20872447729 is the 72237-th centered octagonal number.

It is an amenable number.

20872447729 is a deficient number, since it is larger than the sum of its proper divisors (3408923048).

20872447729 is an frugal number, since it uses more digits than its factorization.

20872447729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41292 (or 20646 counting only the distinct ones).

The product of its (nonzero) digits is 3161088, while the sum is 52.

The spelling of 20872447729 in words is "twenty billion, eight hundred seventy-two million, four hundred forty-seven thousand, seven hundred twenty-nine".