20894480729 has 4 divisors (see below), whose sum is σ = 20988178176. Its totient is φ = 20800783284.

The previous prime is 20894480723. The next prime is 20894480741. The reversal of 20894480729 is 92708449802.

It is a happy number.

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 20894480729 - 2⁴ = 20894480713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20894480723) 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 3 ways as a sum of consecutive naturals, for example, 46848389 + ... + 46848834.

It is an arithmetic number, because the mean of its divisors is an integer number (5247044544).

Almost surely, 2^20894480729 is an apocalyptic number.

It is an amenable number.

20894480729 is a deficient number, since it is larger than the sum of its proper divisors (93697447).

20894480729 is an equidigital number, since it uses as much as digits as its factorization.

20894480729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93697446.

The product of its (nonzero) digits is 2322432, while the sum is 53.

The spelling of 20894480729 in words is "twenty billion, eight hundred ninety-four million, four hundred eighty thousand, seven hundred twenty-nine".