21978476179 has 24 divisors (see below), whose sum is σ = 24744058416. Its totient is φ = 19496769600.

The previous prime is 21978476171. The next prime is 21978476203. The reversal of 21978476179 is 97167487912.

It is not a de Polignac number, because 21978476179 - 2³ = 21978476171 is a prime.

It is a super-3 number, since 3×21978476179³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21978476171) 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 23 ways as a sum of consecutive naturals, for example, 10264449 + ... + 10266589.

It is an arithmetic number, because the mean of its divisors is an integer number (1031002434).

Almost surely, 2^21978476179 is an apocalyptic number.

21978476179 is a deficient number, since it is larger than the sum of its proper divisors (2765582237).

21978476179 is a wasteful number, since it uses less digits than its factorization.

21978476179 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4179 (or 4168 counting only the distinct ones).

The product of its digits is 10668672, while the sum is 61.

The spelling of 21978476179 in words is "twenty-one billion, nine hundred seventy-eight million, four hundred seventy-six thousand, one hundred seventy-nine".