20049979 has 2 divisors, whose sum is σ = 20049980. Its totient is φ = 20049978.

The previous prime is 20049977. The next prime is 20049983. The reversal of 20049979 is 97994002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20049979 - 2¹ = 20049977 is a prime.

Together with 20049977, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20049971) 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 as a sum of consecutive naturals, namely, 10024989 + 10024990.

It is an arithmetic number, because the mean of its divisors is an integer number (10024990).

Almost surely, 2^20049979 is an apocalyptic number.

20049979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20049979 is an equidigital number, since it uses as much as digits as its factorization.

20049979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 20049979 is about 4477.7202905050. The cubic root of 20049979 is about 271.6676800411.

The spelling of 20049979 in words is "twenty million, forty-nine thousand, nine hundred seventy-nine".