20505711423 has 16 divisors (see below), whose sum is σ = 29655321696. Its totient is φ = 12552514560.

The previous prime is 20505711409. The next prime is 20505711463. The reversal of 20505711423 is 32411750502.

It is not a de Polignac number, because 20505711423 - 2²⁶ = 20438602559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505711463) 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 in 15 ways as a sum of consecutive naturals, for example, 4901236 + ... + 4905417.

It is an arithmetic number, because the mean of its divisors is an integer number (1853457606).

Almost surely, 2^20505711423 is an apocalyptic number.

20505711423 is a deficient number, since it is larger than the sum of its proper divisors (9149610273).

20505711423 is a wasteful number, since it uses less digits than its factorization.

20505711423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9806714.

The product of its (nonzero) digits is 8400, while the sum is 30.

The spelling of 20505711423 in words is "twenty billion, five hundred five million, seven hundred eleven thousand, four hundred twenty-three".