20520423901 has 2 divisors, whose sum is σ = 20520423902. Its totient is φ = 20520423900.

The previous prime is 20520423899. The next prime is 20520423943. The reversal of 20520423901 is 10932402502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18864747801 + 1655676100 = 137349^2 + 40690^2 .

It is a cyclic number.

It is not a de Polignac number, because 20520423901 - 2¹ = 20520423899 is a prime.

Together with 20520423899, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20520423901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20520423101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10260211950 + 10260211951.

It is an arithmetic number, because the mean of its divisors is an integer number (10260211951).

Almost surely, 2^20520423901 is an apocalyptic number.

It is an amenable number.

20520423901 is a deficient number, since it is larger than the sum of its proper divisors (1).

20520423901 is an equidigital number, since it uses as much as digits as its factorization.

20520423901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 28.

The spelling of 20520423901 in words is "twenty billion, five hundred twenty million, four hundred twenty-three thousand, nine hundred one".