125216321 has 2 divisors, whose sum is σ = 125216322. Its totient is φ = 125216320.

The previous prime is 125216291. The next prime is 125216323. The reversal of 125216321 is 123612521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90935296 + 34281025 = 9536^2 + 5855^2 .

It is a cyclic number.

It is not a de Polignac number, because 125216321 - 2¹⁸ = 124954177 is a prime.

Together with 125216323, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (125216323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62608160 + 62608161.

It is an arithmetic number, because the mean of its divisors is an integer number (62608161).

Almost surely, 2^125216321 is an apocalyptic number.

It is an amenable number.

125216321 is a deficient number, since it is larger than the sum of its proper divisors (1).

125216321 is an equidigital number, since it uses as much as digits as its factorization.

125216321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

The square root of 125216321 is about 11190.0098748839. The cubic root of 125216321 is about 500.2882617784.

Adding to 125216321 its reverse (123612521), we get a palindrome (248828842).

The spelling of 125216321 in words is "one hundred twenty-five million, two hundred sixteen thousand, three hundred twenty-one".