20543947 has 2 divisors, whose sum is σ = 20543948. Its totient is φ = 20543946.

The previous prime is 20543933. The next prime is 20543951. The reversal of 20543947 is 74934502.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20543947 is a prime.

It is not a weakly prime, because it can be changed into another prime (20543927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10271973 + 10271974.

It is an arithmetic number, because the mean of its divisors is an integer number (10271974).

Almost surely, 2^20543947 is an apocalyptic number.

20543947 is a deficient number, since it is larger than the sum of its proper divisors (1).

20543947 is an equidigital number, since it uses as much as digits as its factorization.

20543947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 20543947 is about 4532.5431051453. The cubic root of 20543947 is about 273.8806155808.

The spelling of 20543947 in words is "twenty million, five hundred forty-three thousand, nine hundred forty-seven".