2171923691 has 8 divisors (see below), whose sum is σ = 2485265664. Its totient is φ = 1859348520.

The previous prime is 2171923661. The next prime is 2171923703. The reversal of 2171923691 is 1963291712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2171923691 - 2¹⁰ = 2171922667 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2171923631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185615 + ... + 196968.

It is an arithmetic number, because the mean of its divisors is an integer number (310658208).

Almost surely, 2^2171923691 is an apocalyptic number.

2171923691 is a deficient number, since it is larger than the sum of its proper divisors (313341973).

2171923691 is an equidigital number, since it uses as much as digits as its factorization.

2171923691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383401.

The product of its digits is 40824, while the sum is 41.

The square root of 2171923691 is about 46603.9021005752. The cubic root of 2171923691 is about 1295.0350444445.

The spelling of 2171923691 in words is "two billion, one hundred seventy-one million, nine hundred twenty-three thousand, six hundred ninety-one".