20978343629 has 8 divisors (see below), whose sum is σ = 21085726200. Its totient is φ = 20871129600.

The previous prime is 20978343619. The next prime is 20978343637. The reversal of 20978343629 is 92634387902.

It can be written as a sum of positive squares in 4 ways, for example, as 8117649604 + 12860694025 = 90098^2 + 113405^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20978343629 - 2¹² = 20978339533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20978343619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211319 + ... + 294299.

It is an arithmetic number, because the mean of its divisors is an integer number (2635715775).

Almost surely, 2^20978343629 is an apocalyptic number.

It is an amenable number.

20978343629 is a deficient number, since it is larger than the sum of its proper divisors (107382571).

20978343629 is a wasteful number, since it uses less digits than its factorization.

20978343629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84271.

The product of its (nonzero) digits is 3919104, while the sum is 53.

The spelling of 20978343629 in words is "twenty billion, nine hundred seventy-eight million, three hundred forty-three thousand, six hundred twenty-nine".