21212221007 has 2 divisors, whose sum is σ = 21212221008. Its totient is φ = 21212221006.

The previous prime is 21212220949. The next prime is 21212221049. The reversal of 21212221007 is 70012221212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21212221007 - 2⁶ = 21212220943 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21212221007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212221307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606110503 + 10606110504.

It is an arithmetic number, because the mean of its divisors is an integer number (10606110504).

Almost surely, 2^21212221007 is an apocalyptic number.

21212221007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212221007 is an equidigital number, since it uses as much as digits as its factorization.

21212221007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 21212221007 its reverse (70012221212), we get a palindrome (91224442219).

The spelling of 21212221007 in words is "twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, seven".