20479139 has 2 divisors, whose sum is σ = 20479140. Its totient is φ = 20479138.

The previous prime is 20479117. The next prime is 20479141. The reversal of 20479139 is 93197402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20479139 - 2¹² = 20475043 is a prime.

Together with 20479141, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20479099 and 20479108.

It is not a weakly prime, because it can be changed into another prime (20479159) 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, 10239569 + 10239570.

It is an arithmetic number, because the mean of its divisors is an integer number (10239570).

Almost surely, 2^20479139 is an apocalyptic number.

20479139 is a deficient number, since it is larger than the sum of its proper divisors (1).

20479139 is an equidigital number, since it uses as much as digits as its factorization.

20479139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 20479139 is about 4525.3882706349. The cubic root of 20479139 is about 273.5923173278.

The spelling of 20479139 in words is "twenty million, four hundred seventy-nine thousand, one hundred thirty-nine".