19651989909 has 16 divisors (see below), whose sum is σ = 26658095360. Its totient is φ = 12874023360.

The previous prime is 19651989901. The next prime is 19651989913. The reversal of 19651989909 is 90998915691.

It is not a de Polignac number, because 19651989909 - 2³ = 19651989901 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19651989909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19651989901) 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, 138459 + ... + 241815.

It is an arithmetic number, because the mean of its divisors is an integer number (1666130960).

Almost surely, 2^19651989909 is an apocalyptic number.

It is an amenable number.

19651989909 is a deficient number, since it is larger than the sum of its proper divisors (7006105451).

19651989909 is a wasteful number, since it uses less digits than its factorization.

19651989909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104460.

The product of its (nonzero) digits is 14171760, while the sum is 66.

The spelling of 19651989909 in words is "nineteen billion, six hundred fifty-one million, nine hundred eighty-nine thousand, nine hundred nine".