2166881623 has 4 divisors (see below), whose sum is σ = 2168183160. Its totient is φ = 2165580088.

The previous prime is 2166881569. The next prime is 2166881669. The reversal of 2166881623 is 3261886612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2166881623 - 2⁹ = 2166881111 is a prime.

It is a super-2 number, since 2×2166881623² = 9390751936190228258, which contains 22 as substring.

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 2166881623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166882623) 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, 648268 + ... + 651601.

It is an arithmetic number, because the mean of its divisors is an integer number (542045790).

Almost surely, 2^2166881623 is an apocalyptic number.

2166881623 is a deficient number, since it is larger than the sum of its proper divisors (1301537).

2166881623 is a wasteful number, since it uses less digits than its factorization.

2166881623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1301536.

The product of its digits is 165888, while the sum is 43.

The square root of 2166881623 is about 46549.7757567101. The cubic root of 2166881623 is about 1294.0321371874.

The spelling of 2166881623 in words is "two billion, one hundred sixty-six million, eight hundred eighty-one thousand, six hundred twenty-three".