31430321 has 4 divisors (see below), whose sum is σ = 33848052. Its totient is φ = 29012592.

The previous prime is 31430293. The next prime is 31430323. The reversal of 31430321 is 12303413.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12303413 = 23 ⋅534931.

It can be written as a sum of positive squares in 2 ways, for example, as 10627600 + 20802721 = 3260^2 + 4561^2 .

It is a cyclic number.

It is not a de Polignac number, because 31430321 - 2⁶ = 31430257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31430321.

It is not an unprimeable number, because it can be changed into a prime (31430323) 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, 1208846 + ... + 1208871.

It is an arithmetic number, because the mean of its divisors is an integer number (8462013).

Almost surely, 2^31430321 is an apocalyptic number.

It is an amenable number.

31430321 is a deficient number, since it is larger than the sum of its proper divisors (2417731).

31430321 is a wasteful number, since it uses less digits than its factorization.

31430321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2417730.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 31430321 is about 5606.2751448711. The cubic root of 31430321 is about 315.5849415030.

Adding to 31430321 its reverse (12303413), we get a palindrome (43733734).

The spelling of 31430321 in words is "thirty-one million, four hundred thirty thousand, three hundred twenty-one".