2172222864 has 120 divisors (see below), whose sum is σ = 6983570880. Its totient is φ = 617428224.

The previous prime is 2172222863. The next prime is 2172222869. The reversal of 2172222864 is 4682222712.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (2172222863) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 193107 + ... + 204045.

It is an arithmetic number, because the mean of its divisors is an integer number (58196424).

Almost surely, 2^2172222864 is an apocalyptic number.

2172222864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2172222864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3491785440).

2172222864 is an abundant number, since it is smaller than the sum of its proper divisors (4811348016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2172222864 is a wasteful number, since it uses less digits than its factorization.

2172222864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11157 (or 11148 counting only the distinct ones).

The product of its digits is 43008, while the sum is 36.

The square root of 2172222864 is about 46607.1117320093. Note that the first 3 decimals coincide. The cubic root of 2172222864 is about 1295.0945035211.

It can be divided in two parts, 217 and 2222864, that added together give a square (2223081 = 1491²).

The spelling of 2172222864 in words is "two billion, one hundred seventy-two million, two hundred twenty-two thousand, eight hundred sixty-four".