145602221 has 4 divisors (see below), whose sum is σ = 146061852. Its totient is φ = 145142592.

The previous prime is 145602217. The next prime is 145602227. The reversal of 145602221 is 122206541.

It is a happy number.

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 20475625 + 125126596 = 4525^2 + 11186^2 .

It is a cyclic number.

It is not a de Polignac number, because 145602221 - 2² = 145602217 is a prime.

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 (145602227) 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, 229340 + ... + 229973.

It is an arithmetic number, because the mean of its divisors is an integer number (36515463).

Almost surely, 2^145602221 is an apocalyptic number.

It is an amenable number.

145602221 is a deficient number, since it is larger than the sum of its proper divisors (459631).

145602221 is an equidigital number, since it uses as much as digits as its factorization.

145602221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459630.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 145602221 is about 12066.5745346391. The cubic root of 145602221 is about 526.0850978185.

Adding to 145602221 its reverse (122206541), we get a palindrome (267808762).

The spelling of 145602221 in words is "one hundred forty-five million, six hundred two thousand, two hundred twenty-one".