20523139121 has 2 divisors, whose sum is σ = 20523139122. Its totient is φ = 20523139120.

The previous prime is 20523139099. The next prime is 20523139139. The reversal of 20523139121 is 12193132502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17466265600 + 3056873521 = 132160^2 + 55289^2 .

It is a cyclic number.

It is not a de Polignac number, because 20523139121 - 2⁶ = 20523139057 is a prime.

It is not a weakly prime, because it can be changed into another prime (20523139181) 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, 10261569560 + 10261569561.

It is an arithmetic number, because the mean of its divisors is an integer number (10261569561).

Almost surely, 2^20523139121 is an apocalyptic number.

It is an amenable number.

20523139121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20523139121 is an equidigital number, since it uses as much as digits as its factorization.

20523139121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 29.

The spelling of 20523139121 in words is "twenty billion, five hundred twenty-three million, one hundred thirty-nine thousand, one hundred twenty-one".