20499847 has 2 divisors, whose sum is σ = 20499848. Its totient is φ = 20499846.

The previous prime is 20499833. The next prime is 20499893. The reversal of 20499847 is 74899402.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20499847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20499827) 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, 10249923 + 10249924.

It is an arithmetic number, because the mean of its divisors is an integer number (10249924).

Almost surely, 2^20499847 is an apocalyptic number.

20499847 is a deficient number, since it is larger than the sum of its proper divisors (1).

20499847 is an equidigital number, since it uses as much as digits as its factorization.

20499847 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 20499847 is about 4527.6756730137. The cubic root of 20499847 is about 273.6845028629.

The spelling of 20499847 in words is "twenty million, four hundred ninety-nine thousand, eight hundred forty-seven".