20154323521 has 2 divisors, whose sum is σ = 20154323522. Its totient is φ = 20154323520.

The previous prime is 20154323509. The next prime is 20154323537. The reversal of 20154323521 is 12532345102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16037689600 + 4116633921 = 126640^2 + 64161^2 .

It is a cyclic number.

It is not a de Polignac number, because 20154323521 - 2¹³ = 20154315329 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20154323521.

It is not a weakly prime, because it can be changed into another prime (20154323821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077161760 + 10077161761.

It is an arithmetic number, because the mean of its divisors is an integer number (10077161761).

Almost surely, 2^20154323521 is an apocalyptic number.

It is an amenable number.

20154323521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20154323521 is an equidigital number, since it uses as much as digits as its factorization.

20154323521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 20154323521 its reverse (12532345102), we get a palindrome (32686668623).

The spelling of 20154323521 in words is "twenty billion, one hundred fifty-four million, three hundred twenty-three thousand, five hundred twenty-one".