145421321 has 2 divisors, whose sum is σ = 145421322. Its totient is φ = 145421320.

The previous prime is 145421317. The next prime is 145421323. The reversal of 145421321 is 123124541.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96924025 + 48497296 = 9845^2 + 6964^2 .

It is a cyclic number.

It is not a de Polignac number, because 145421321 - 2² = 145421317 is a prime.

It is a super-2 number, since 2×145421321² = 42294721202770082, which contains 22 as substring.

Together with 145421323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (145421323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72710660 + 72710661.

It is an arithmetic number, because the mean of its divisors is an integer number (72710661).

Almost surely, 2^145421321 is an apocalyptic number.

It is an amenable number.

145421321 is a deficient number, since it is larger than the sum of its proper divisors (1).

145421321 is an equidigital number, since it uses as much as digits as its factorization.

145421321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 23.

The square root of 145421321 is about 12059.0762913251. The cubic root of 145421321 is about 525.8671335728.

Adding to 145421321 its reverse (123124541), we get a palindrome (268545862).

The spelling of 145421321 in words is "one hundred forty-five million, four hundred twenty-one thousand, three hundred twenty-one".