20555947 has 2 divisors, whose sum is σ = 20555948. Its totient is φ = 20555946.

The previous prime is 20555923. The next prime is 20555957. The reversal of 20555947 is 74955502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20555947 - 2⁷ = 20555819 is a prime.

It is not a weakly prime, because it can be changed into another prime (20555957) 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, 10277973 + 10277974.

It is an arithmetic number, because the mean of its divisors is an integer number (10277974).

Almost surely, 2^20555947 is an apocalyptic number.

20555947 is a deficient number, since it is larger than the sum of its proper divisors (1).

20555947 is an equidigital number, since it uses as much as digits as its factorization.

20555947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63000, while the sum is 37.

The square root of 20555947 is about 4533.8666720582. The cubic root of 20555947 is about 273.9339310040.

The spelling of 20555947 in words is "twenty million, five hundred fifty-five thousand, nine hundred forty-seven".