321720479 has 4 divisors (see below), whose sum is σ = 322381584. Its totient is φ = 321059376.

The previous prime is 321720467. The next prime is 321720523. The reversal of 321720479 is 974027123.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 974027123 = 2411 ⋅403993.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321720479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321720419) 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, 329822 + ... + 330795.

It is an arithmetic number, because the mean of its divisors is an integer number (80595396).

Almost surely, 2^321720479 is an apocalyptic number.

321720479 is a deficient number, since it is larger than the sum of its proper divisors (661105).

321720479 is an equidigital number, since it uses as much as digits as its factorization.

321720479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661104.

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 321720479 is about 17936.5682057633. The cubic root of 321720479 is about 685.2140123740.

The spelling of 321720479 in words is "three hundred twenty-one million, seven hundred twenty thousand, four hundred seventy-nine".