321344721 has 6 divisors (see below), whose sum is σ = 464164610. Its totient is φ = 214229808.

The previous prime is 321344717. The next prime is 321344743. The reversal of 321344721 is 127443123.

It is a happy number.

321344721 is a `hidden beast` number, since 3 + 213 + 447 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 302760000 + 18584721 = 17400^2 + 4311^2 .

It is not a de Polignac number, because 321344721 - 2² = 321344717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321346721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17852476 + ... + 17852493.

Almost surely, 2^321344721 is an apocalyptic number.

It is an amenable number.

321344721 is a deficient number, since it is larger than the sum of its proper divisors (142819889).

321344721 is a wasteful number, since it uses less digits than its factorization.

321344721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35704975 (or 35704972 counting only the distinct ones).

The product of its digits is 4032, while the sum is 27.

The square root of 321344721 is about 17926.0905107611. The cubic root of 321344721 is about 684.9471399706.

Adding to 321344721 its reverse (127443123), we get a palindrome (448787844).

The spelling of 321344721 in words is "three hundred twenty-one million, three hundred forty-four thousand, seven hundred twenty-one".