20392696809 has 81 divisors (see below), whose sum is σ = 32097789399. Its totient is φ = 12955088160.

The previous prime is 20392696781. The next prime is 20392696829. The reversal of 20392696809 is 90869629302.

The square root of 20392696809 is 142803.

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., 982634409 + 19410062400 = 31347^2 + 139320^2 .

It is a tau number, because it is divible by the number of its divisors (81).

It is not a de Polignac number, because 20392696809 - 2¹¹ = 20392694761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20392696829) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 474248742 + ... + 474248784.

Almost surely, 2^20392696809 is an apocalyptic number.

20392696809 is the 142803-rd square number.

20392696809 is the 71402-nd centered octagonal number.

It is an amenable number.

20392696809 is a deficient number, since it is larger than the sum of its proper divisors (11705092590).

20392696809 is an frugal number, since it uses more digits than its factorization.

20392696809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 2519424, while the sum is 54.

The spelling of 20392696809 in words is "twenty billion, three hundred ninety-two million, six hundred ninety-six thousand, eight hundred nine".