19621121709 has 16 divisors (see below), whose sum is σ = 29911178880. Its totient is φ = 11207447040.

The previous prime is 19621121669. The next prime is 19621121783. The reversal of 19621121709 is 90712112691.

It is not a de Polignac number, because 19621121709 - 2¹⁹ = 19620597421 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19621171709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140124 + ... + 242645.

It is an arithmetic number, because the mean of its divisors is an integer number (1869448680).

Almost surely, 2^19621121709 is an apocalyptic number.

It is an amenable number.

19621121709 is a deficient number, since it is larger than the sum of its proper divisors (10290057171).

19621121709 is a wasteful number, since it uses less digits than its factorization.

19621121709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385220.

The product of its (nonzero) digits is 13608, while the sum is 39.

The spelling of 19621121709 in words is "nineteen billion, six hundred twenty-one million, one hundred twenty-one thousand, seven hundred nine".