145217809 has 8 divisors (see below), whose sum is σ = 158729760. Its totient is φ = 131757600.

The previous prime is 145217803. The next prime is 145217833. The reversal of 145217809 is 908712541.

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 145217809 - 2²⁷ = 11000081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145217803) 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 7 ways as a sum of consecutive naturals, for example, 6939 + ... + 18400.

It is an arithmetic number, because the mean of its divisors is an integer number (19841220).

Almost surely, 2^145217809 is an apocalyptic number.

It is an amenable number.

145217809 is a deficient number, since it is larger than the sum of its proper divisors (13511951).

145217809 is a wasteful number, since it uses less digits than its factorization.

145217809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25871.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 145217809 is about 12050.6352114733. The cubic root of 145217809 is about 525.6217082255.

The spelling of 145217809 in words is "one hundred forty-five million, two hundred seventeen thousand, eight hundred nine".