19664309121 has 16 divisors (see below), whose sum is σ = 26713108800. Its totient is φ = 12864645440.

The previous prime is 19664309107. The next prime is 19664309129. The reversal of 19664309121 is 12190346691.

It is a cyclic number.

It is not a de Polignac number, because 19664309121 - 2¹¹ = 19664307073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19664309129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 227910 + ... + 302111.

It is an arithmetic number, because the mean of its divisors is an integer number (1669569300).

Almost surely, 2^19664309121 is an apocalyptic number.

It is an amenable number.

19664309121 is a deficient number, since it is larger than the sum of its proper divisors (7048799679).

19664309121 is a wasteful number, since it uses less digits than its factorization.

19664309121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530256.

The product of its (nonzero) digits is 69984, while the sum is 42.

The spelling of 19664309121 in words is "nineteen billion, six hundred sixty-four million, three hundred nine thousand, one hundred twenty-one".