20945471771 has 4 divisors (see below), whose sum is σ = 23937682032. Its totient is φ = 17953261512.

The previous prime is 20945471753. The next prime is 20945471777. The reversal of 20945471771 is 17717454902.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20945471771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20945471777) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1496105120 + ... + 1496105133.

It is an arithmetic number, because the mean of its divisors is an integer number (5984420508).

Almost surely, 2^20945471771 is an apocalyptic number.

20945471771 is a deficient number, since it is larger than the sum of its proper divisors (2992210261).

20945471771 is an equidigital number, since it uses as much as digits as its factorization.

20945471771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2992210260.

The product of its (nonzero) digits is 493920, while the sum is 47.

The spelling of 20945471771 in words is "twenty billion, nine hundred forty-five million, four hundred seventy-one thousand, seven hundred seventy-one".