21435403453 has 2 divisors, whose sum is σ = 21435403454. Its totient is φ = 21435403452.

The previous prime is 21435403391. The next prime is 21435403469. The reversal of 21435403453 is 35430453412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18919177209 + 2516226244 = 137547^2 + 50162^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21435403453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21435403553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10717701726 + 10717701727.

It is an arithmetic number, because the mean of its divisors is an integer number (10717701727).

Almost surely, 2^21435403453 is an apocalyptic number.

It is an amenable number.

21435403453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21435403453 is an equidigital number, since it uses as much as digits as its factorization.

21435403453 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 34.

Adding to 21435403453 its reverse (35430453412), we get a palindrome (56865856865).

The spelling of 21435403453 in words is "twenty-one billion, four hundred thirty-five million, four hundred three thousand, four hundred fifty-three".