145287581 has 4 divisors (see below), whose sum is σ = 145387164. Its totient is φ = 145188000.

The previous prime is 145287563. The next prime is 145287601. The reversal of 145287581 is 185782541.

145287581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 185782541 = 7 ⋅26540363.

It can be written as a sum of positive squares in 2 ways, for example, as 32205625 + 113081956 = 5675^2 + 10634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145287581 is a prime.

It is a super-2 number, since 2×145287581² = 42216962385663122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145287551) 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, 47570 + ... + 50531.

It is an arithmetic number, because the mean of its divisors is an integer number (36346791).

Almost surely, 2^145287581 is an apocalyptic number.

It is an amenable number.

145287581 is a deficient number, since it is larger than the sum of its proper divisors (99583).

145287581 is an equidigital number, since it uses as much as digits as its factorization.

145287581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99582.

The product of its digits is 89600, while the sum is 41.

The square root of 145287581 is about 12053.5298149546. The cubic root of 145287581 is about 525.7058756018.

The spelling of 145287581 in words is "one hundred forty-five million, two hundred eighty-seven thousand, five hundred eighty-one".