145705221 has 12 divisors (see below), whose sum is σ = 211979040. Its totient is φ = 96437160.

The previous prime is 145705201. The next prime is 145705229. The reversal of 145705221 is 122507541.

It is not a de Polignac number, because 145705221 - 2⁷ = 145705093 is a prime.

It is a super-2 number, since 2×145705221² = 42460022853317682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145705229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56985 + ... + 59486.

It is an arithmetic number, because the mean of its divisors is an integer number (17664920).

Almost surely, 2^145705221 is an apocalyptic number.

It is an amenable number.

145705221 is a deficient number, since it is larger than the sum of its proper divisors (66273819).

145705221 is a wasteful number, since it uses less digits than its factorization.

145705221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116616 (or 116613 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 145705221 is about 12070.8417684932. The cubic root of 145705221 is about 526.2091206353.

It can be divided in two parts, 14570 and 5221, that added together give a palindrome (19791).

The spelling of 145705221 in words is "one hundred forty-five million, seven hundred five thousand, two hundred twenty-one".