21500524413121 has 32 divisors (see below), whose sum is σ = 24914595888000. Its totient is φ = 18387627429888.

The previous prime is 21500524413113. The next prime is 21500524413131. The reversal of 21500524413121 is 12131442500512.

It is a cyclic number.

It is not a de Polignac number, because 21500524413121 - 2³ = 21500524413113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21500524413131) 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 31 ways as a sum of consecutive naturals, for example, 1009606 + ... + 6634783.

It is an arithmetic number, because the mean of its divisors is an integer number (778581121500).

Almost surely, 2^{21500524413121} is an apocalyptic number.

It is an amenable number.

21500524413121 is a deficient number, since it is larger than the sum of its proper divisors (3414071474879).

21500524413121 is a wasteful number, since it uses less digits than its factorization.

21500524413121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7644673.

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 21500524413121 its reverse (12131442500512), we get a palindrome (33631966913633).

The spelling of 21500524413121 in words is "twenty-one trillion, five hundred billion, five hundred twenty-four million, four hundred thirteen thousand, one hundred twenty-one".