145867221 has 6 divisors (see below), whose sum is σ = 210697110. Its totient is φ = 97244808.

The previous prime is 145867201. The next prime is 145867229. The reversal of 145867221 is 122768541.

145867221 is a `hidden beast` number, since 1 + 4 + 586 + 72 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 136188900 + 9678321 = 11670^2 + 3111^2 .

It is not a de Polignac number, because 145867221 - 2²⁶ = 78758357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145867229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8103726 + ... + 8103743.

It is an arithmetic number, because the mean of its divisors is an integer number (35116185).

Almost surely, 2^145867221 is an apocalyptic number.

It is an amenable number.

145867221 is a deficient number, since it is larger than the sum of its proper divisors (64829889).

145867221 is a wasteful number, since it uses less digits than its factorization.

145867221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16207475 (or 16207472 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 145867221 is about 12077.5502896904. The cubic root of 145867221 is about 526.4040674449.

The spelling of 145867221 in words is "one hundred forty-five million, eight hundred sixty-seven thousand, two hundred twenty-one".