20111947 has 2 divisors, whose sum is σ = 20111948. Its totient is φ = 20111946.

The previous prime is 20111941. The next prime is 20111981. The reversal of 20111947 is 74911102.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20111947 is a prime.

It is not a weakly prime, because it can be changed into another prime (20111941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055973 + 10055974.

It is an arithmetic number, because the mean of its divisors is an integer number (10055974).

Almost surely, 2^20111947 is an apocalyptic number.

20111947 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111947 is an equidigital number, since it uses as much as digits as its factorization.

20111947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 20111947 is about 4484.6345447539. The cubic root of 20111947 is about 271.9472711730.

The spelling of 20111947 in words is "twenty million, one hundred eleven thousand, nine hundred forty-seven".