145677221 has 4 divisors (see below), whose sum is σ = 146014092. Its totient is φ = 145340352.

The previous prime is 145677197. The next prime is 145677241. The reversal of 145677221 is 122776541.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11464996 + 134212225 = 3386^2 + 11585^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145677221 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 (145677241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167786 + ... + 168651.

It is an arithmetic number, because the mean of its divisors is an integer number (36503523).

Almost surely, 2^145677221 is an apocalyptic number.

It is an amenable number.

145677221 is a deficient number, since it is larger than the sum of its proper divisors (336871).

145677221 is an equidigital number, since it uses as much as digits as its factorization.

145677221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336870.

The product of its digits is 23520, while the sum is 35.

The square root of 145677221 is about 12069.6818930741. The cubic root of 145677221 is about 526.1754114811.

The spelling of 145677221 in words is "one hundred forty-five million, six hundred seventy-seven thousand, two hundred twenty-one".