20417187979 has 8 divisors (see below), whose sum is σ = 21531513680. Its totient is φ = 19306836000.

The previous prime is 20417187949. The next prime is 20417187991. The reversal of 20417187979 is 97978171402.

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 20417187979 - 2⁷ = 20417187851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20417187949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 982872 + ... + 1003429.

It is an arithmetic number, because the mean of its divisors is an integer number (2691439210).

Almost surely, 2^20417187979 is an apocalyptic number.

20417187979 is a deficient number, since it is larger than the sum of its proper divisors (1114325701).

20417187979 is a wasteful number, since it uses less digits than its factorization.

20417187979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1986861.

The product of its (nonzero) digits is 1778112, while the sum is 55.

The spelling of 20417187979 in words is "twenty billion, four hundred seventeen million, one hundred eighty-seven thousand, nine hundred seventy-nine".