21261034133453 has 16 divisors (see below), whose sum is σ = 22741986097152. Its totient is φ = 19827136560000.

The previous prime is 21261034133411. The next prime is 21261034133461. The reversal of 21261034133453 is 35433143016212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21261034133453 is a prime.

It is a super-2 number, since 2×21261034133453² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21261034133473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6276398 + ... + 9050703.

It is an arithmetic number, because the mean of its divisors is an integer number (1421374131072).

Almost surely, 2^{21261034133453} is an apocalyptic number.

21261034133453 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21261034133453 is a deficient number, since it is larger than the sum of its proper divisors (1480951963699).

21261034133453 is a wasteful number, since it uses less digits than its factorization.

21261034133453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15328636.

The product of its (nonzero) digits is 155520, while the sum is 38.

Adding to 21261034133453 its reverse (35433143016212), we get a palindrome (56694177149665).

The spelling of 21261034133453 in words is "twenty-one trillion, two hundred sixty-one billion, thirty-four million, one hundred thirty-three thousand, four hundred fifty-three".