20517047 has 2 divisors, whose sum is σ = 20517048. Its totient is φ = 20517046.

The previous prime is 20517041. The next prime is 20517059. The reversal of 20517047 is 74071502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20517047 - 2⁴ = 20517031 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20517041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258523 + 10258524.

It is an arithmetic number, because the mean of its divisors is an integer number (10258524).

Almost surely, 2^20517047 is an apocalyptic number.

20517047 is a deficient number, since it is larger than the sum of its proper divisors (1).

20517047 is an equidigital number, since it uses as much as digits as its factorization.

20517047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 20517047 is about 4529.5747040975. The cubic root of 20517047 is about 273.7610246945.

Adding to 20517047 its reverse (74071502), we get a palindrome (94588549).

The spelling of 20517047 in words is "twenty million, five hundred seventeen thousand, forty-seven".