321120021 has 16 divisors (see below), whose sum is σ = 453890304. Its totient is φ = 201245184.

The previous prime is 321120017. The next prime is 321120029. The reversal of 321120021 is 120021123.

It is not a de Polignac number, because 321120021 - 2² = 321120017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 321119979 and 321120006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321120029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45300 + ... + 51906.

It is an arithmetic number, because the mean of its divisors is an integer number (28368144).

Almost surely, 2^321120021 is an apocalyptic number.

It is an amenable number.

321120021 is a deficient number, since it is larger than the sum of its proper divisors (132770283).

321120021 is a wasteful number, since it uses less digits than its factorization.

321120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7580.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 321120021 is about 17919.8220136250. The cubic root of 321120021 is about 684.7874531924.

Adding to 321120021 its reverse (120021123), we get a palindrome (441141144).

It can be divided in two parts, 3211 and 20021, that added together give a palindrome (23232).

The spelling of 321120021 in words is "three hundred twenty-one million, one hundred twenty thousand, twenty-one".