145316221 has 16 divisors (see below), whose sum is σ = 158241600. Its totient is φ = 132910848.

The previous prime is 145316191. The next prime is 145316243. The reversal of 145316221 is 122613541.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145316221 is a prime.

It is a super-2 number, since 2×145316221² = 42233608171441682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145316261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196270 + ... + 197008.

It is an arithmetic number, because the mean of its divisors is an integer number (9890100).

Almost surely, 2^145316221 is an apocalyptic number.

It is an amenable number.

145316221 is a deficient number, since it is larger than the sum of its proper divisors (12925379).

145316221 is a wasteful number, since it uses less digits than its factorization.

145316221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1068.

The product of its digits is 1440, while the sum is 25.

The square root of 145316221 is about 12054.7177901434. The cubic root of 145316221 is about 525.7404168130.

Adding to 145316221 its reverse (122613541), we get a palindrome (267929762).

The spelling of 145316221 in words is "one hundred forty-five million, three hundred sixteen thousand, two hundred twenty-one".