20979446851 has 8 divisors (see below), whose sum is σ = 22989302784. Its totient is φ = 18986696520.

The previous prime is 20979446827. The next prime is 20979446863. The reversal of 20979446851 is 15864497902.

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

It is not a de Polignac number, because 20979446851 - 2⁹ = 20979446339 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20979446792 and 20979446801.

It is not an unprimeable number, because it can be changed into a prime (20979446951) 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, 4273831 + ... + 4278736.

It is an arithmetic number, because the mean of its divisors is an integer number (2873662848).

Almost surely, 2^20979446851 is an apocalyptic number.

20979446851 is a deficient number, since it is larger than the sum of its proper divisors (2009855933).

20979446851 is a wasteful number, since it uses less digits than its factorization.

20979446851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8552801.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 20979446851 in words is "twenty billion, nine hundred seventy-nine million, four hundred forty-six thousand, eight hundred fifty-one".