21212012047 has 2 divisors, whose sum is σ = 21212012048. Its totient is φ = 21212012046.

The previous prime is 21212012033. The next prime is 21212012069. The reversal of 21212012047 is 74021021212.

It is an a-pointer prime, because the next prime (21212012069) can be obtained adding 21212012047 to its sum of digits (22).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212012047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212010047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606006023 + 10606006024.

It is an arithmetic number, because the mean of its divisors is an integer number (10606006024).

Almost surely, 2^21212012047 is an apocalyptic number.

21212012047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212012047 is an equidigital number, since it uses as much as digits as its factorization.

21212012047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 22.

Adding to 21212012047 its reverse (74021021212), we get a palindrome (95233033259).

The spelling of 21212012047 in words is "twenty-one billion, two hundred twelve million, twelve thousand, forty-seven".