20923517437 has 2 divisors, whose sum is σ = 20923517438. Its totient is φ = 20923517436.

The previous prime is 20923517411. The next prime is 20923517443. The reversal of 20923517437 is 73471532902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19920781881 + 1002735556 = 141141^2 + 31666^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20923517437 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20923517393 and 20923517402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20923517467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10461758718 + 10461758719.

It is an arithmetic number, because the mean of its divisors is an integer number (10461758719).

Almost surely, 2^20923517437 is an apocalyptic number.

It is an amenable number.

20923517437 is a deficient number, since it is larger than the sum of its proper divisors (1).

20923517437 is an equidigital number, since it uses as much as digits as its factorization.

20923517437 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 317520, while the sum is 43.

The spelling of 20923517437 in words is "twenty billion, nine hundred twenty-three million, five hundred seventeen thousand, four hundred thirty-seven".