145500221 has 8 divisors (see below), whose sum is σ = 151480920. Its totient is φ = 139583808.

The previous prime is 145500193. The next prime is 145500227. The reversal of 145500221 is 122005541.

It can be written as a sum of positive squares in 4 ways, for example, as 28622500 + 116877721 = 5350^2 + 10811^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 145500221 - 2¹⁰ = 145499197 is a prime.

It is a super-2 number, since 2×145500221² = 42340628622097682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 145500193 and 145500202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145500227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11426 + ... + 20531.

It is an arithmetic number, because the mean of its divisors is an integer number (18935115).

Almost surely, 2^145500221 is an apocalyptic number.

It is an amenable number.

145500221 is a deficient number, since it is larger than the sum of its proper divisors (5980699).

145500221 is a wasteful number, since it uses less digits than its factorization.

145500221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32143.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 145500221 is about 12062.3472425561. The cubic root of 145500221 is about 525.9622214527.

Adding to 145500221 its reverse (122005541), we get a palindrome (267505762).

The spelling of 145500221 in words is "one hundred forty-five million, five hundred thousand, two hundred twenty-one".