145223989 has 2 divisors, whose sum is σ = 145223990. Its totient is φ = 145223988.

The previous prime is 145223987. The next prime is 145224071. The reversal of 145223989 is 989322541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133217764 + 12006225 = 11542^2 + 3465^2 .

It is an emirp because it is prime and its reverse (989322541) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 145223989 - 2¹ = 145223987 is a prime.

Together with 145223987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (145223983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72611994 + 72611995.

It is an arithmetic number, because the mean of its divisors is an integer number (72611995).

Almost surely, 2^145223989 is an apocalyptic number.

It is an amenable number.

145223989 is a deficient number, since it is larger than the sum of its proper divisors (1).

145223989 is an equidigital number, since it uses as much as digits as its factorization.

145223989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 43.

The square root of 145223989 is about 12050.8916267636. The cubic root of 145223989 is about 525.6291643727.

The spelling of 145223989 in words is "one hundred forty-five million, two hundred twenty-three thousand, nine hundred eighty-nine".