20129120639 has 4 divisors (see below), whose sum is σ = 20133304224. Its totient is φ = 20124937056.

The previous prime is 20129120633. The next prime is 20129120647. The reversal of 20129120639 is 93602192102.

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-20129120639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20129120599 and 20129120608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20129120633) 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, 2084567 + ... + 2094200.

It is an arithmetic number, because the mean of its divisors is an integer number (5033326056).

Almost surely, 2^20129120639 is an apocalyptic number.

20129120639 is a deficient number, since it is larger than the sum of its proper divisors (4183585).

20129120639 is an equidigital number, since it uses as much as digits as its factorization.

20129120639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4183584.

The product of its (nonzero) digits is 11664, while the sum is 35.

The spelling of 20129120639 in words is "twenty billion, one hundred twenty-nine million, one hundred twenty thousand, six hundred thirty-nine".