145742321 has 2 divisors, whose sum is σ = 145742322. Its totient is φ = 145742320.

The previous prime is 145742291. The next prime is 145742341. The reversal of 145742321 is 123247541.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89567296 + 56175025 = 9464^2 + 7495^2 .

It is an emirp because it is prime and its reverse (123247541) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145742321 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (145742341) 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 as a sum of consecutive naturals, namely, 72871160 + 72871161.

It is an arithmetic number, because the mean of its divisors is an integer number (72871161).

Almost surely, 2^145742321 is an apocalyptic number.

It is an amenable number.

145742321 is a deficient number, since it is larger than the sum of its proper divisors (1).

145742321 is an equidigital number, since it uses as much as digits as its factorization.

145742321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 29.

The square root of 145742321 is about 12072.3784317756. The cubic root of 145742321 is about 526.2537786133.

Adding to 145742321 its reverse (123247541), we get a palindrome (268989862).

The spelling of 145742321 in words is "one hundred forty-five million, seven hundred forty-two thousand, three hundred twenty-one".