20744678739 has 4 divisors (see below), whose sum is σ = 27659571656. Its totient is φ = 13829785824.

The previous prime is 20744678737. The next prime is 20744678753. The reversal of 20744678739 is 93787644702.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20744678739 - 2¹ = 20744678737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20744678737) 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, 3457446454 + ... + 3457446459.

It is an arithmetic number, because the mean of its divisors is an integer number (6914892914).

Almost surely, 2^20744678739 is an apocalyptic number.

20744678739 is a deficient number, since it is larger than the sum of its proper divisors (6914892917).

20744678739 is an equidigital number, since it uses as much as digits as its factorization.

20744678739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6914892916.

The product of its (nonzero) digits is 14224896, while the sum is 57.

The spelling of 20744678739 in words is "twenty billion, seven hundred forty-four million, six hundred seventy-eight thousand, seven hundred thirty-nine".