145221331 has 2 divisors, whose sum is σ = 145221332. Its totient is φ = 145221330.

The previous prime is 145221289. The next prime is 145221367. The reversal of 145221331 is 133122541.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (133122541) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 145221331 - 2⁷ = 145221203 is a prime.

It is a super-2 number, since 2×145221331² = 42178469954823122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (145221031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72610665 + 72610666.

It is an arithmetic number, because the mean of its divisors is an integer number (72610666).

Almost surely, 2^145221331 is an apocalyptic number.

145221331 is a deficient number, since it is larger than the sum of its proper divisors (1).

145221331 is an equidigital number, since it uses as much as digits as its factorization.

145221331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 22.

The square root of 145221331 is about 12050.7813439627. The cubic root of 145221331 is about 525.6259575314.

Adding to 145221331 its reverse (133122541), we get a palindrome (278343872).

The spelling of 145221331 in words is "one hundred forty-five million, two hundred twenty-one thousand, three hundred thirty-one".