2172321207 has 32 divisors (see below), whose sum is σ = 3681244160. Its totient is φ = 1240233120.

The previous prime is 2172321199. The next prime is 2172321233. The reversal of 2172321207 is 7021232712.

It is not a de Polignac number, because 2172321207 - 2³ = 2172321199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172321007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 241857 + ... + 250677.

It is an arithmetic number, because the mean of its divisors is an integer number (115038880).

Almost surely, 2^2172321207 is an apocalyptic number.

2172321207 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

2172321207 is a deficient number, since it is larger than the sum of its proper divisors (1508922953).

2172321207 is a wasteful number, since it uses less digits than its factorization.

2172321207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10140 (or 10134 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 2172321207 is about 46608.1667414628. The cubic root of 2172321207 is about 1295.1140474883.

Adding to 2172321207 its reverse (7021232712), we get a palindrome (9193553919).

The spelling of 2172321207 in words is "two billion, one hundred seventy-two million, three hundred twenty-one thousand, two hundred seven".