21415225213 has 2 divisors, whose sum is σ = 21415225214. Its totient is φ = 21415225212.

The previous prime is 21415225211. The next prime is 21415225243. The reversal of 21415225213 is 31252251412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19095646969 + 2319578244 = 138187^2 + 48162^2 .

It is a cyclic number.

It is not a de Polignac number, because 21415225213 - 2¹ = 21415225211 is a prime.

It is a super-2 number, since 2×21415225213² (a number of 21 digits) contains 22 as substring.

Together with 21415225211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21415225211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10707612606 + 10707612607.

It is an arithmetic number, because the mean of its divisors is an integer number (10707612607).

Almost surely, 2^21415225213 is an apocalyptic number.

It is an amenable number.

21415225213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21415225213 is an equidigital number, since it uses as much as digits as its factorization.

21415225213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4800, while the sum is 28.

Adding to 21415225213 its reverse (31252251412), we get a palindrome (52667476625).

The spelling of 21415225213 in words is "twenty-one billion, four hundred fifteen million, two hundred twenty-five thousand, two hundred thirteen".