2171321251 has 16 divisors (see below), whose sum is σ = 2474615808. Its totient is φ = 1887213600.

The previous prime is 2171321227. The next prime is 2171321293. The reversal of 2171321251 is 1521231712.

It is a cyclic number.

It is not a de Polignac number, because 2171321251 - 2⁷ = 2171321123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2171321221) 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 15 ways as a sum of consecutive naturals, for example, 10056 + ... + 66661.

It is an arithmetic number, because the mean of its divisors is an integer number (154663488).

Almost surely, 2^2171321251 is an apocalyptic number.

2171321251 is a deficient number, since it is larger than the sum of its proper divisors (303294557).

2171321251 is a wasteful number, since it uses less digits than its factorization.

2171321251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76842.

The product of its digits is 840, while the sum is 25.

The square root of 2171321251 is about 46597.4382450366. The cubic root of 2171321251 is about 1294.9152960603.

Adding to 2171321251 its reverse (1521231712), we get a palindrome (3692552963).

The spelling of 2171321251 in words is "two billion, one hundred seventy-one million, three hundred twenty-one thousand, two hundred fifty-one".