20520340673 has 4 divisors (see below), whose sum is σ = 23451817920. Its totient is φ = 17588863428.

The previous prime is 20520340609. The next prime is 20520340741. The reversal of 20520340673 is 37604302502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20520340673 - 2⁶ = 20520340609 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20520340273) 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, 1465738613 + ... + 1465738626.

It is an arithmetic number, because the mean of its divisors is an integer number (5862954480).

Almost surely, 2^20520340673 is an apocalyptic number.

It is an amenable number.

20520340673 is a deficient number, since it is larger than the sum of its proper divisors (2931477247).

20520340673 is an equidigital number, since it uses as much as digits as its factorization.

20520340673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2931477246.

The product of its (nonzero) digits is 30240, while the sum is 32.

The spelling of 20520340673 in words is "twenty billion, five hundred twenty million, three hundred forty thousand, six hundred seventy-three".