20765577217 has 16 divisors (see below), whose sum is σ = 26000687232. Its totient is φ = 16111509120.

The previous prime is 20765577187. The next prime is 20765577227. The reversal of 20765577217 is 71277556702.

It is a happy number.

It is not a de Polignac number, because 20765577217 - 2⁷ = 20765577089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20765577227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 560778 + ... + 596659.

It is an arithmetic number, because the mean of its divisors is an integer number (1625042952).

Almost surely, 2^20765577217 is an apocalyptic number.

It is an amenable number.

20765577217 is a deficient number, since it is larger than the sum of its proper divisors (5235110015).

20765577217 is a wasteful number, since it uses less digits than its factorization.

20765577217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157688.

The product of its (nonzero) digits is 1440600, while the sum is 49.

The spelling of 20765577217 in words is "twenty billion, seven hundred sixty-five million, five hundred seventy-seven thousand, two hundred seventeen".