20809164734 has 16 divisors (see below), whose sum is σ = 31529224080. Its totient is φ = 10299465600.

The previous prime is 20809164731. The next prime is 20809164763. The reversal of 20809164734 is 43746190802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20809164731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1567577 + ... + 1580795.

It is an arithmetic number, because the mean of its divisors is an integer number (1970576505).

Almost surely, 2^20809164734 is an apocalyptic number.

20809164734 is a deficient number, since it is larger than the sum of its proper divisors (10720059346).

20809164734 is a wasteful number, since it uses less digits than its factorization.

20809164734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21115.

The product of its (nonzero) digits is 290304, while the sum is 44.

The spelling of 20809164734 in words is "twenty billion, eight hundred nine million, one hundred sixty-four thousand, seven hundred thirty-four".