145215281 has 4 divisors (see below), whose sum is σ = 145368612. Its totient is φ = 145061952.

The previous prime is 145215277. The next prime is 145215293. The reversal of 145215281 is 182512541.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69872881 + 75342400 = 8359^2 + 8680^2 .

It is a cyclic number.

It is not a de Polignac number, because 145215281 - 2² = 145215277 is a prime.

It is a super-2 number, since 2×145215281² = 42174955671817922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145215211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75236 + ... + 77141.

It is an arithmetic number, because the mean of its divisors is an integer number (36342153).

Almost surely, 2^145215281 is an apocalyptic number.

It is an amenable number.

145215281 is a deficient number, since it is larger than the sum of its proper divisors (153331).

145215281 is an equidigital number, since it uses as much as digits as its factorization.

145215281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153330.

The product of its digits is 3200, while the sum is 29.

The square root of 145215281 is about 12050.5303202805. The cubic root of 145215281 is about 525.6186581418.

The spelling of 145215281 in words is "one hundred forty-five million, two hundred fifteen thousand, two hundred eighty-one".