2109872651989 has 4 divisors (see below), whose sum is σ = 2109880378656. Its totient is φ = 2109864925324.

The previous prime is 2109872651959. The next prime is 2109872652001. The reversal of 2109872651989 is 9891562789012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2109872651989 - 2²⁷ = 2109738434261 is a prime.

It is a super-2 number, since 2×2109872651989² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2109872651959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3438139 + ... + 4005064.

It is an arithmetic number, because the mean of its divisors is an integer number (527470094664).

Almost surely, 2^{2109872651989} is an apocalyptic number.

It is an amenable number.

2109872651989 is a deficient number, since it is larger than the sum of its proper divisors (7726667).

2109872651989 is an equidigital number, since it uses as much as digits as its factorization.

2109872651989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7726666.

The product of its (nonzero) digits is 39191040, while the sum is 67.

The spelling of 2109872651989 in words is "two trillion, one hundred nine billion, eight hundred seventy-two million, six hundred fifty-one thousand, nine hundred eighty-nine".