20510719939 has 4 divisors (see below), whose sum is σ = 20858359320. Its totient is φ = 20163080560.

The previous prime is 20510719919. The next prime is 20510719949. The reversal of 20510719939 is 93991701502.

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-20510719939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20510719919) 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, 173819602 + ... + 173819719.

It is an arithmetic number, because the mean of its divisors is an integer number (5214589830).

Almost surely, 2^20510719939 is an apocalyptic number.

20510719939 is a deficient number, since it is larger than the sum of its proper divisors (347639381).

20510719939 is an equidigital number, since it uses as much as digits as its factorization.

20510719939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347639380.

The product of its (nonzero) digits is 153090, while the sum is 46.

The spelling of 20510719939 in words is "twenty billion, five hundred ten million, seven hundred nineteen thousand, nine hundred thirty-nine".