20479999 has 2 divisors, whose sum is σ = 20480000. Its totient is φ = 20479998.

The previous prime is 20479937. The next prime is 20480011. The reversal of 20479999 is 99997402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20479999 - 2¹⁹ = 19955711 is a prime.

20479999 is a modest number, since divided by 9999 gives 2047 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20479909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10239999 + 10240000.

It is an arithmetic number, because the mean of its divisors is an integer number (10240000).

Almost surely, 2^20479999 is an apocalyptic number.

20479999 is a deficient number, since it is larger than the sum of its proper divisors (1).

20479999 is an equidigital number, since it uses as much as digits as its factorization.

20479999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 367416, while the sum is 49.

The square root of 20479999 is about 4525.4832891085. The cubic root of 20479999 is about 273.5961470152.

The spelling of 20479999 in words is "twenty million, four hundred seventy-nine thousand, nine hundred ninety-nine".