31428112321 has 2 divisors, whose sum is σ = 31428112322. Its totient is φ = 31428112320.

The previous prime is 31428112307. The next prime is 31428112337. The reversal of 31428112321 is 12321182413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22849647921 + 8578464400 = 151161^2 + 92620^2 .

It is a cyclic number.

It is not a de Polignac number, because 31428112321 - 2²¹ = 31426015169 is a prime.

It is a super-2 number, since 2×31428112321² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31428112321.

It is not a weakly prime, because it can be changed into another prime (31428112361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15714056160 + 15714056161.

It is an arithmetic number, because the mean of its divisors is an integer number (15714056161).

Almost surely, 2^31428112321 is an apocalyptic number.

It is an amenable number.

31428112321 is a deficient number, since it is larger than the sum of its proper divisors (1).

31428112321 is an equidigital number, since it uses as much as digits as its factorization.

31428112321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 28.

Adding to 31428112321 its reverse (12321182413), we get a palindrome (43749294734).

The spelling of 31428112321 in words is "thirty-one billion, four hundred twenty-eight million, one hundred twelve thousand, three hundred twenty-one".