145257221 has 8 divisors (see below), whose sum is σ = 148874880. Its totient is φ = 141684192.

The previous prime is 145257193. The next prime is 145257239. The reversal of 145257221 is 122752541.

It is a happy number.

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 145257221 - 2⁶ = 145257157 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 (145257241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4520 + ... + 17633.

It is an arithmetic number, because the mean of its divisors is an integer number (18609360).

Almost surely, 2^145257221 is an apocalyptic number.

It is an amenable number.

145257221 is a deficient number, since it is larger than the sum of its proper divisors (3617659).

145257221 is an equidigital number, since it uses as much as digits as its factorization.

145257221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22315.

The product of its digits is 5600, while the sum is 29.

The square root of 145257221 is about 12052.2703670304. The cubic root of 145257221 is about 525.6692550314.

The spelling of 145257221 in words is "one hundred forty-five million, two hundred fifty-seven thousand, two hundred twenty-one".