20404864747 has 4 divisors (see below), whose sum is σ = 20956347616. Its totient is φ = 19853381880.

The previous prime is 20404864721. The next prime is 20404864751. The reversal of 20404864747 is 74746840402.

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-20404864747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20404864697 and 20404864706.

It is not an unprimeable number, because it can be changed into a prime (20404864757) 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, 275741379 + ... + 275741452.

It is an arithmetic number, because the mean of its divisors is an integer number (5239086904).

Almost surely, 2^20404864747 is an apocalyptic number.

20404864747 is a deficient number, since it is larger than the sum of its proper divisors (551482869).

20404864747 is an equidigital number, since it uses as much as digits as its factorization.

20404864747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551482868.

The product of its (nonzero) digits is 1204224, while the sum is 46.

The spelling of 20404864747 in words is "twenty billion, four hundred four million, eight hundred sixty-four thousand, seven hundred forty-seven".