20475245730721 has 4 divisors (see below), whose sum is σ = 20475254829232. Its totient is φ = 20475236632212.

The previous prime is 20475245730703. The next prime is 20475245730749. The reversal of 20475245730721 is 12703754257402.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20475245730721 - 2²⁷ = 20475111512993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20475245730521) 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, 1570306 + ... + 6589108.

It is an arithmetic number, because the mean of its divisors is an integer number (5118813707308).

Almost surely, 2^{20475245730721} is an apocalyptic number.

It is an amenable number.

20475245730721 is a deficient number, since it is larger than the sum of its proper divisors (9098511).

20475245730721 is an equidigital number, since it uses as much as digits as its factorization.

20475245730721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9098510.

The product of its (nonzero) digits is 3292800, while the sum is 49.

The spelling of 20475245730721 in words is "twenty trillion, four hundred seventy-five billion, two hundred forty-five million, seven hundred thirty thousand, seven hundred twenty-one".