7123216321 has 24 divisors (see below), whose sum is σ = 8005210560. Its totient is φ = 6327921600.

The previous prime is 7123216273. The next prime is 7123216333. The reversal of 7123216321 is 1236123217.

7123216321 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7123216321 - 2⁹ = 7123215809 is a prime.

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 7123216321.

It is not an unprimeable number, because it can be changed into a prime (7123216351) 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, 1620036 + ... + 1624426.

It is an arithmetic number, because the mean of its divisors is an integer number (333550440).

Almost surely, 2^7123216321 is an apocalyptic number.

It is an amenable number.

7123216321 is a deficient number, since it is larger than the sum of its proper divisors (881994239).

7123216321 is a wasteful number, since it uses less digits than its factorization.

7123216321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4777 (or 4764 counting only the distinct ones).

The product of its digits is 3024, while the sum is 28.

The square root of 7123216321 is about 84399.1488167979. The cubic root of 7123216321 is about 1924.0899793565.

Adding to 7123216321 its reverse (1236123217), we get a palindrome (8359339538).

The spelling of 7123216321 in words is "seven billion, one hundred twenty-three million, two hundred sixteen thousand, three hundred twenty-one".