20009441521 has 2 divisors, whose sum is σ = 20009441522. Its totient is φ = 20009441520.

The previous prime is 20009441497. The next prime is 20009441539. The reversal of 20009441521 is 12514490002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17998905600 + 2010535921 = 134160^2 + 44839^2 .

It is a cyclic number.

It is not a de Polignac number, because 20009441521 - 2²⁵ = 19975887089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20009441521.

It is not a weakly prime, because it can be changed into another prime (20009441561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10004720760 + 10004720761.

It is an arithmetic number, because the mean of its divisors is an integer number (10004720761).

Almost surely, 2^20009441521 is an apocalyptic number.

It is an amenable number.

20009441521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20009441521 is an equidigital number, since it uses as much as digits as its factorization.

20009441521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 28.

The spelling of 20009441521 in words is "twenty billion, nine million, four hundred forty-one thousand, five hundred twenty-one".