21453025520521 has 16 divisors (see below), whose sum is σ = 24686687652480. Its totient is φ = 18261720771840.

The previous prime is 21453025520501. The next prime is 21453025520557. The reversal of 21453025520521 is 12502552035412.

It is not a de Polignac number, because 21453025520521 - 2³⁵ = 21418665782153 is a prime.

It is a super-2 number, since 2×21453025520521² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21453025520501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2932336 + ... + 7176673.

It is an arithmetic number, because the mean of its divisors is an integer number (1542917978280).

Almost surely, 2^{21453025520521} is an apocalyptic number.

It is an amenable number.

21453025520521 is a deficient number, since it is larger than the sum of its proper divisors (3233662131959).

21453025520521 is a wasteful number, since it uses less digits than its factorization.

21453025520521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10111104.

The product of its (nonzero) digits is 120000, while the sum is 37.

Adding to 21453025520521 its reverse (12502552035412), we get a palindrome (33955577555933).

The spelling of 21453025520521 in words is "twenty-one trillion, four hundred fifty-three billion, twenty-five million, five hundred twenty thousand, five hundred twenty-one".