21210212078453 has 2 divisors, whose sum is σ = 21210212078454. Its totient is φ = 21210212078452.

The previous prime is 21210212078431. The next prime is 21210212078467. The reversal of 21210212078453 is 35487021201212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17240781448804 + 3969430629649 = 4152202^2 + 1992343^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210212078453 - 2¹⁰ = 21210212077429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210212078753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605106039226 + 10605106039227.

It is an arithmetic number, because the mean of its divisors is an integer number (10605106039227).

Almost surely, 2^{21210212078453} is an apocalyptic number.

It is an amenable number.

21210212078453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210212078453 is an equidigital number, since it uses as much as digits as its factorization.

21210212078453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 53760, while the sum is 38.

Adding to 21210212078453 its reverse (35487021201212), we get a palindrome (56697233279665).

The spelling of 21210212078453 in words is "twenty-one trillion, two hundred ten billion, two hundred twelve million, seventy-eight thousand, four hundred fifty-three".