351220321 has 4 divisors (see below), whose sum is σ = 351274500. Its totient is φ = 351166144.

The previous prime is 351220319. The next prime is 351220343. The reversal of 351220321 is 123022153.

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 170694225 + 180526096 = 13065^2 + 13436^2 .

It is a cyclic number.

It is not a de Polignac number, because 351220321 - 2¹ = 351220319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (351220351) 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, 15796 + ... + 30853.

It is an arithmetic number, because the mean of its divisors is an integer number (87818625).

Almost surely, 2^351220321 is an apocalyptic number.

It is an amenable number.

351220321 is a deficient number, since it is larger than the sum of its proper divisors (54179).

351220321 is an equidigital number, since it uses as much as digits as its factorization.

351220321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54178.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 351220321 is about 18740.8730052791. The cubic root of 351220321 is about 705.5479675856.

Adding to 351220321 its reverse (123022153), we get a palindrome (474242474).

It can be divided in two parts, 351220 and 321, that added together give a triangular number (351541 = T₈₃₈).

The spelling of 351220321 in words is "three hundred fifty-one million, two hundred twenty thousand, three hundred twenty-one".