20213979 has 8 divisors (see below), whose sum is σ = 27008832. Its totient is φ = 13447560.

The previous prime is 20213959. The next prime is 20213981. The reversal of 20213979 is 97931202.

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

It is not a de Polignac number, because 20213979 - 2¹¹ = 20211931 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (20213959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5389 + ... + 8334.

It is an arithmetic number, because the mean of its divisors is an integer number (3376104).

Almost surely, 2^20213979 is an apocalyptic number.

20213979 is a deficient number, since it is larger than the sum of its proper divisors (6794853).

20213979 is a wasteful number, since it uses less digits than its factorization.

20213979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14217.

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 20213979 is about 4495.9958852294. The cubic root of 20213979 is about 272.4063769501.

The spelling of 20213979 in words is "twenty million, two hundred thirteen thousand, nine hundred seventy-nine".