145209309 has 8 divisors (see below), whose sum is σ = 221271360. Its totient is φ = 82976736.

The previous prime is 145209299. The next prime is 145209371. The reversal of 145209309 is 903902541.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 145209309 - 2⁹ = 145208797 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 145209309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145209109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3457344 + ... + 3457385.

It is an arithmetic number, because the mean of its divisors is an integer number (27658920).

Almost surely, 2^145209309 is an apocalyptic number.

It is an amenable number.

145209309 is a deficient number, since it is larger than the sum of its proper divisors (76062051).

145209309 is an equidigital number, since it uses as much as digits as its factorization.

145209309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6914739.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 145209309 is about 12050.2825278082. The cubic root of 145209309 is about 525.6114526613.

The spelling of 145209309 in words is "one hundred forty-five million, two hundred nine thousand, three hundred nine".