145331993 has 2 divisors, whose sum is σ = 145331994. Its totient is φ = 145331992.

The previous prime is 145331981. The next prime is 145332013. The reversal of 145331993 is 399133541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 112933129 + 32398864 = 10627^2 + 5692^2 .

It is a cyclic number.

It is not a de Polignac number, because 145331993 - 2²⁰ = 144283417 is a prime.

It is a super-2 number, since 2×145331993² = 42242776378704098, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (145331933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72665996 + 72665997.

It is an arithmetic number, because the mean of its divisors is an integer number (72665997).

Almost surely, 2^145331993 is an apocalyptic number.

It is an amenable number.

145331993 is a deficient number, since it is larger than the sum of its proper divisors (1).

145331993 is an equidigital number, since it uses as much as digits as its factorization.

145331993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43740, while the sum is 38.

The square root of 145331993 is about 12055.3719561032. The cubic root of 145331993 is about 525.7594366623.

The spelling of 145331993 in words is "one hundred forty-five million, three hundred thirty-one thousand, nine hundred ninety-three".