20216947 has 2 divisors, whose sum is σ = 20216948. Its totient is φ = 20216946.

The previous prime is 20216941. The next prime is 20216951. The reversal of 20216947 is 74961202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20216947 - 2³ = 20216939 is a prime.

It is not a weakly prime, because it can be changed into another prime (20216941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10108473 + 10108474.

It is an arithmetic number, because the mean of its divisors is an integer number (10108474).

Almost surely, 2^20216947 is an apocalyptic number.

20216947 is a deficient number, since it is larger than the sum of its proper divisors (1).

20216947 is an equidigital number, since it uses as much as digits as its factorization.

20216947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20216947 is about 4496.3259445908. The cubic root of 20216947 is about 272.4197086905.

The spelling of 20216947 in words is "twenty million, two hundred sixteen thousand, nine hundred forty-seven".