21418849513 has 2 divisors, whose sum is σ = 21418849514. Its totient is φ = 21418849512.

The previous prime is 21418849489. The next prime is 21418849531. The reversal of 21418849513 is 31594881412.

Together with next prime (21418849531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18309337344 + 3109512169 = 135312^2 + 55763^2 .

It is a cyclic number.

It is not a de Polignac number, because 21418849513 - 2¹³ = 21418841321 is a prime.

It is a super-2 number, since 2×21418849513² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21418843513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10709424756 + 10709424757.

It is an arithmetic number, because the mean of its divisors is an integer number (10709424757).

Almost surely, 2^21418849513 is an apocalyptic number.

It is an amenable number.

21418849513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21418849513 is an equidigital number, since it uses as much as digits as its factorization.

21418849513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 276480, while the sum is 46.

The spelling of 21418849513 in words is "twenty-one billion, four hundred eighteen million, eight hundred forty-nine thousand, five hundred thirteen".