21215416331 has 2 divisors, whose sum is σ = 21215416332. Its totient is φ = 21215416330.

The previous prime is 21215416279. The next prime is 21215416357. The reversal of 21215416331 is 13361451212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21215416331 - 2¹⁰ = 21215415307 is a prime.

It is a super-2 number, since 2×21215416331² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21215416294 and 21215416303.

It is not a weakly prime, because it can be changed into another prime (21215416381) 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, 10607708165 + 10607708166.

It is an arithmetic number, because the mean of its divisors is an integer number (10607708166).

Almost surely, 2^21215416331 is an apocalyptic number.

21215416331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21215416331 is an equidigital number, since it uses as much as digits as its factorization.

21215416331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 29.

Adding to 21215416331 its reverse (13361451212), we get a palindrome (34576867543).

The spelling of 21215416331 in words is "twenty-one billion, two hundred fifteen million, four hundred sixteen thousand, three hundred thirty-one".