19689000805 has 16 divisors (see below), whose sum is σ = 24175350000. Its totient is φ = 15388968960.

The previous prime is 19689000787. The next prime is 19689000811. The reversal of 19689000805 is 50800098691.

It can be written as a sum of positive squares in 8 ways, for example, as 1292690116 + 18396310689 = 35954^2 + 135633^2 .

It is not a de Polignac number, because 19689000805 - 2²¹ = 19686903653 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171180 + ... + 262069.

It is an arithmetic number, because the mean of its divisors is an integer number (1510959375).

Almost surely, 2^19689000805 is an apocalyptic number.

It is an amenable number.

19689000805 is a deficient number, since it is larger than the sum of its proper divisors (4486349195).

19689000805 is a wasteful number, since it uses less digits than its factorization.

19689000805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433464.

The product of its (nonzero) digits is 155520, while the sum is 46.

The spelling of 19689000805 in words is "nineteen billion, six hundred eighty-nine million, eight hundred five", and thus it is an aban number.