21454523152405 has 32 divisors (see below), whose sum is σ = 29457965053440. Its totient is φ = 14694367887360.

The previous prime is 21454523152397. The next prime is 21454523152409. The reversal of 21454523152405 is 50425132545412.

It is not a de Polignac number, because 21454523152405 - 2³ = 21454523152397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21454523152409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 259922181 + ... + 260004709.

It is an arithmetic number, because the mean of its divisors is an integer number (920561407920).

Almost surely, 2^{21454523152405} is an apocalyptic number.

It is an amenable number.

21454523152405 is a deficient number, since it is larger than the sum of its proper divisors (8003441901035).

21454523152405 is an equidigital number, since it uses as much as digits as its factorization.

21454523152405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91189.

The product of its (nonzero) digits is 960000, while the sum is 43.

Adding to 21454523152405 its reverse (50425132545412), we get a palindrome (71879655697817).

The spelling of 21454523152405 in words is "twenty-one trillion, four hundred fifty-four billion, five hundred twenty-three million, one hundred fifty-two thousand, four hundred five".