20385271729 has 9 divisors (see below), whose sum is σ = 20703786201. Its totient is φ = 20071590660.

The previous prime is 20385271723. The next prime is 20385271747. The reversal of 20385271729 is 92717258302.

The square root of 20385271729 is 142777.

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

It is a de Polignac number, because none of the positive numbers 2^k-20385271729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20385271723) 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, 9564994 + ... + 9567124.

It is an arithmetic number, because the mean of its divisors is an integer number (2300420689).

Almost surely, 2^20385271729 is an apocalyptic number.

20385271729 is the 142777-th square number.

20385271729 is the 71389-th centered octagonal number.

It is an amenable number.

20385271729 is a deficient number, since it is larger than the sum of its proper divisors (318514472).

20385271729 is an frugal number, since it uses more digits than its factorization.

20385271729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4396 (or 2198 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 46.

The spelling of 20385271729 in words is "twenty billion, three hundred eighty-five million, two hundred seventy-one thousand, seven hundred twenty-nine".