21520501404089 has 2 divisors, whose sum is σ = 21520501404090. Its totient is φ = 21520501404088.

The previous prime is 21520501403987. The next prime is 21520501404113. The reversal of 21520501404089 is 98040410502512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16458599886400 + 5061901517689 = 4056920^2 + 2249867^2 .

It is a cyclic number.

It is not a de Polignac number, because 21520501404089 - 2⁸ = 21520501403833 is a prime.

It is not a weakly prime, because it can be changed into another prime (21520501404989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10760250702044 + 10760250702045.

It is an arithmetic number, because the mean of its divisors is an integer number (10760250702045).

Almost surely, 2^{21520501404089} is an apocalyptic number.

It is an amenable number.

21520501404089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21520501404089 is an equidigital number, since it uses as much as digits as its factorization.

21520501404089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 115200, while the sum is 41.

The spelling of 21520501404089 in words is "twenty-one trillion, five hundred twenty billion, five hundred one million, four hundred four thousand, eighty-nine".