145231997 has 2 divisors, whose sum is σ = 145231998. Its totient is φ = 145231996.

The previous prime is 145231979. The next prime is 145232039. The reversal of 145231997 is 799132541.

Together with previous prime (145231979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141824281 + 3407716 = 11909^2 + 1846^2 .

It is an emirp because it is prime and its reverse (799132541) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145231997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (145231907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72615998 + 72615999.

It is an arithmetic number, because the mean of its divisors is an integer number (72615999).

Almost surely, 2^145231997 is an apocalyptic number.

It is an amenable number.

145231997 is a deficient number, since it is larger than the sum of its proper divisors (1).

145231997 is an equidigital number, since it uses as much as digits as its factorization.

145231997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 41.

The square root of 145231997 is about 12051.2238797559. The cubic root of 145231997 is about 525.6388256805.

The spelling of 145231997 in words is "one hundred forty-five million, two hundred thirty-one thousand, nine hundred ninety-seven".