31431361 has 4 divisors (see below), whose sum is σ = 33849172. Its totient is φ = 29013552.

The previous prime is 31431343. The next prime is 31431373. The reversal of 31431361 is 16313413.

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: 16313413 = 61 ⋅267433.

It can be written as a sum of positive squares in 2 ways, for example, as 13104400 + 18326961 = 3620^2 + 4281^2 .

It is a cyclic number.

It is not a de Polignac number, because 31431361 - 2⁷ = 31431233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31431311) 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, 1208886 + ... + 1208911.

It is an arithmetic number, because the mean of its divisors is an integer number (8462293).

Almost surely, 2^31431361 is an apocalyptic number.

It is an amenable number.

31431361 is a deficient number, since it is larger than the sum of its proper divisors (2417811).

31431361 is a wasteful number, since it uses less digits than its factorization.

31431361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2417810.

The product of its digits is 648, while the sum is 22.

The square root of 31431361 is about 5606.3678973111. The cubic root of 31431361 is about 315.5884222684.

Adding to 31431361 its reverse (16313413), we get a palindrome (47744774).

The spelling of 31431361 in words is "thirty-one million, four hundred thirty-one thousand, three hundred sixty-one".