145510221 has 4 divisors (see below), whose sum is σ = 194013632. Its totient is φ = 97006812.

The previous prime is 145510219. The next prime is 145510229. The reversal of 145510221 is 122015541.

145510221 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 145510221 - 2¹ = 145510219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145510229) 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, 24251701 + ... + 24251706.

It is an arithmetic number, because the mean of its divisors is an integer number (48503408).

Almost surely, 2^145510221 is an apocalyptic number.

It is an amenable number.

145510221 is a deficient number, since it is larger than the sum of its proper divisors (48503411).

145510221 is an equidigital number, since it uses as much as digits as its factorization.

145510221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48503410.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 145510221 is about 12062.7617484555. The cubic root of 145510221 is about 525.9742706937.

Adding to 145510221 its reverse (122015541), we get a palindrome (267525762).

The spelling of 145510221 in words is "one hundred forty-five million, five hundred ten thousand, two hundred twenty-one".