21504153242413 has 2 divisors, whose sum is σ = 21504153242414. Its totient is φ = 21504153242412.

The previous prime is 21504153242399. The next prime is 21504153242431. The reversal of 21504153242413 is 31424235140512.

Together with next prime (21504153242431) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11605345982244 + 9898807260169 = 3406662^2 + 3146237^2 .

It is a cyclic number.

It is not a de Polignac number, because 21504153242413 - 2³³ = 21495563307821 is a prime.

It is a super-2 number, since 2×21504153242413² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21504153242443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10752076621206 + 10752076621207.

It is an arithmetic number, because the mean of its divisors is an integer number (10752076621207).

Almost surely, 2^{21504153242413} is an apocalyptic number.

It is an amenable number.

21504153242413 is a deficient number, since it is larger than the sum of its proper divisors (1).

21504153242413 is an equidigital number, since it uses as much as digits as its factorization.

21504153242413 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 115200, while the sum is 37.

Adding to 21504153242413 its reverse (31424235140512), we get a palindrome (52928388382925).

The spelling of 21504153242413 in words is "twenty-one trillion, five hundred four billion, one hundred fifty-three million, two hundred forty-two thousand, four hundred thirteen".