345120321 has 16 divisors (see below), whose sum is σ = 566351744. Its totient is φ = 182041344.

The previous prime is 345120319. The next prime is 345120331. The reversal of 345120321 is 123021543.

It is not a de Polignac number, because 345120321 - 2¹ = 345120319 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (345120311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 631816 + ... + 632361.

It is an arithmetic number, because the mean of its divisors is an integer number (35396984).

Almost surely, 2^345120321 is an apocalyptic number.

It is an amenable number.

345120321 is a deficient number, since it is larger than the sum of its proper divisors (221231423).

345120321 is a wasteful number, since it uses less digits than its factorization.

345120321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1264200.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 345120321 is about 18577.4142710981. The cubic root of 345120321 is about 701.4394332548.

Adding to 345120321 its reverse (123021543), we get a palindrome (468141864).

The spelling of 345120321 in words is "three hundred forty-five million, one hundred twenty thousand, three hundred twenty-one".