31109440 has 56 divisors (see below), whose sum is σ = 75236832. Its totient is φ = 12249600.

The previous prime is 31109437. The next prime is 31109443. The reversal of 31109440 is 4490113.

It is an interprime number because it is at equal distance from previous prime (31109437) and next prime (31109443).

It is a super-2 number, since 2×31109440² = 1935594514227200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31109443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20715 + ... + 22165.

Almost surely, 2^31109440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31109440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37618416).

31109440 is an abundant number, since it is smaller than the sum of its proper divisors (44127392).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31109440 is a wasteful number, since it uses less digits than its factorization.

31109440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1535 (or 1525 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 31109440 is about 5577.5837062298. The cubic root of 31109440 is about 314.5073006411.

Adding to 31109440 its reverse (4490113), we get a palindrome (35599553).

The spelling of 31109440 in words is "thirty-one million, one hundred nine thousand, four hundred forty".