21231310207 has 2 divisors, whose sum is σ = 21231310208. Its totient is φ = 21231310206.

The previous prime is 21231310171. The next prime is 21231310223. The reversal of 21231310207 is 70201313212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21231310207 - 2¹⁵ = 21231277439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231310297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615655103 + 10615655104.

It is an arithmetic number, because the mean of its divisors is an integer number (10615655104).

Almost surely, 2^21231310207 is an apocalyptic number.

21231310207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231310207 is an equidigital number, since it uses as much as digits as its factorization.

21231310207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 22.

Adding to 21231310207 its reverse (70201313212), we get a palindrome (91432623419).

The spelling of 21231310207 in words is "twenty-one billion, two hundred thirty-one million, three hundred ten thousand, two hundred seven".