20651047 has 2 divisors, whose sum is σ = 20651048. Its totient is φ = 20651046.

The previous prime is 20651041. The next prime is 20651063. The reversal of 20651047 is 74015602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20651047 is a prime.

It is equal to p_1309228 and since 20651047 and 1309228 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20651041) 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, 10325523 + 10325524.

It is an arithmetic number, because the mean of its divisors is an integer number (10325524).

Almost surely, 2^20651047 is an apocalyptic number.

20651047 is a deficient number, since it is larger than the sum of its proper divisors (1).

20651047 is an equidigital number, since it uses as much as digits as its factorization.

20651047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 20651047 is about 4544.3423066490. The cubic root of 20651047 is about 274.3557237095.

Adding to 20651047 its reverse (74015602), we get a palindrome (94666649).

The spelling of 20651047 in words is "twenty million, six hundred fifty-one thousand, forty-seven".