31430042321 has 4 divisors (see below), whose sum is σ = 31434428772. Its totient is φ = 31425655872.

The previous prime is 31430042299. The next prime is 31430042333. The reversal of 31430042321 is 12324003413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12324003413 = 2531 ⋅4869223.

It can be written as a sum of positive squares in 2 ways, for example, as 30675771025 + 754271296 = 175145^2 + 27464^2 .

It is a cyclic number.

It is not a de Polignac number, because 31430042321 - 2²² = 31425848017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31430042341) 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, 2182460 + ... + 2196813.

It is an arithmetic number, because the mean of its divisors is an integer number (7858607193).

Almost surely, 2^31430042321 is an apocalyptic number.

It is an amenable number.

31430042321 is a deficient number, since it is larger than the sum of its proper divisors (4386451).

31430042321 is an equidigital number, since it uses as much as digits as its factorization.

31430042321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4386450.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 31430042321 its reverse (12324003413), we get a palindrome (43754045734).

The spelling of 31430042321 in words is "thirty-one billion, four hundred thirty million, forty-two thousand, three hundred twenty-one".