20004979 has 2 divisors, whose sum is σ = 20004980. Its totient is φ = 20004978.

The previous prime is 20004977. The next prime is 20004997. The reversal of 20004979 is 97940002.

Together with next prime (20004997) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20004979 - 2¹ = 20004977 is a prime.

Together with 20004977, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20004979.

It is not a weakly prime, because it can be changed into another prime (20004973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10002489 + 10002490.

It is an arithmetic number, because the mean of its divisors is an integer number (10002490).

Almost surely, 2^20004979 is an apocalyptic number.

20004979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20004979 is an equidigital number, since it uses as much as digits as its factorization.

20004979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 20004979 is about 4472.6925894812. The cubic root of 20004979 is about 271.4642849327.

The spelling of 20004979 in words is "twenty million, four thousand, nine hundred seventy-nine".