2166546921 has 64 divisors (see below), whose sum is σ = 3694657536. Its totient is φ = 1096603200.

The previous prime is 2166546901. The next prime is 2166546947. The reversal of 2166546921 is 1296456612.

It is not a de Polignac number, because 2166546921 - 2¹¹ = 2166544873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2166546901) 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 63 ways as a sum of consecutive naturals, for example, 4679136 + ... + 4679598.

It is an arithmetic number, because the mean of its divisors is an integer number (57729024).

Almost surely, 2^2166546921 is an apocalyptic number.

2166546921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2166546921 is a deficient number, since it is larger than the sum of its proper divisors (1528110615).

2166546921 is a wasteful number, since it uses less digits than its factorization.

2166546921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 962.

The product of its digits is 155520, while the sum is 42.

The square root of 2166546921 is about 46546.1805199954. The cubic root of 2166546921 is about 1293.9655072676.

It can be divided in two parts, 21665 and 46921, that added together give a palindrome (68586).

The spelling of 2166546921 in words is "two billion, one hundred sixty-six million, five hundred forty-six thousand, nine hundred twenty-one".