31440361 has 4 divisors (see below), whose sum is σ = 33289812. Its totient is φ = 29590912.

The previous prime is 31440347. The next prime is 31440371. The reversal of 31440361 is 16304413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16304413 = 19 ⋅858127.

It can be written as a sum of positive squares in 2 ways, for example, as 25190361 + 6250000 = 5019^2 + 2500^2 .

It is a cyclic number.

It is not a de Polignac number, because 31440361 - 2¹³ = 31432169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31440371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 924700 + ... + 924733.

It is an arithmetic number, because the mean of its divisors is an integer number (8322453).

Almost surely, 2^31440361 is an apocalyptic number.

It is an amenable number.

31440361 is a deficient number, since it is larger than the sum of its proper divisors (1849451).

31440361 is a wasteful number, since it uses less digits than its factorization.

31440361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1849450.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 31440361 is about 5607.1704985670. The cubic root of 31440361 is about 315.6185410697.

Adding to 31440361 its reverse (16304413), we get a palindrome (47744774).

The spelling of 31440361 in words is "thirty-one million, four hundred forty thousand, three hundred sixty-one".