145372321 has 4 divisors (see below), whose sum is σ = 153923652. Its totient is φ = 136820992.

The previous prime is 145372309. The next prime is 145372327. The reversal of 145372321 is 123273541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123273541 = 179 ⋅688679.

It can be written as a sum of positive squares in 2 ways, for example, as 126787600 + 18584721 = 11260^2 + 4311^2 .

It is a cyclic number.

It is not a de Polignac number, because 145372321 - 2⁷ = 145372193 is a prime.

It is a super-2 number, since 2×145372321² = 42266223425854082, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 145372321.

It is not an unprimeable number, because it can be changed into a prime (145372327) 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 in 3 ways as a sum of consecutive naturals, for example, 4275640 + ... + 4275673.

It is an arithmetic number, because the mean of its divisors is an integer number (38480913).

Almost surely, 2^145372321 is an apocalyptic number.

It is an amenable number.

145372321 is a deficient number, since it is larger than the sum of its proper divisors (8551331).

145372321 is an equidigital number, since it uses as much as digits as its factorization.

145372321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8551330.

The product of its digits is 5040, while the sum is 28.

The square root of 145372321 is about 12057.0444554211. The cubic root of 145372321 is about 525.8080629495.

The spelling of 145372321 in words is "one hundred forty-five million, three hundred seventy-two thousand, three hundred twenty-one".