19958139505 has 24 divisors (see below), whose sum is σ = 25446609000. Its totient is φ = 15024448512.

The previous prime is 19958139491. The next prime is 19958139511. The reversal of 19958139505 is 50593185991.

It can be written as a sum of positive squares in 4 ways, for example, as 3641398336 + 16316741169 = 60344^2 + 127737^2 .

It is not a de Polignac number, because 19958139505 - 2¹³ = 19958131313 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 231841 + ... + 306049.

It is an arithmetic number, because the mean of its divisors is an integer number (1060275375).

Almost surely, 2^19958139505 is an apocalyptic number.

It is an amenable number.

19958139505 is a deficient number, since it is larger than the sum of its proper divisors (5488469495).

19958139505 is a wasteful number, since it uses less digits than its factorization.

19958139505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74401 (or 74382 counting only the distinct ones).

The product of its (nonzero) digits is 2187000, while the sum is 55.

It can be divided in two parts, 199581 and 39505, that added together give a triangular number (239086 = T₆₉₁).

The spelling of 19958139505 in words is "nineteen billion, nine hundred fifty-eight million, one hundred thirty-nine thousand, five hundred five".