31106640 has 160 divisors (see below), whose sum is σ = 103136256. Its totient is φ = 7741440.

The previous prime is 31106633. The next prime is 31106653. The reversal of 31106640 is 4660113.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 275224 + ... + 275336.

Almost surely, 2^31106640 is an apocalyptic number.

31106640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31106640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51568128).

31106640 is an abundant number, since it is smaller than the sum of its proper divisors (72029616).

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

31106640 is a wasteful number, since it uses less digits than its factorization.

31106640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 31106640 is about 5577.3326958323. The cubic root of 31106640 is about 314.4978646322.

Adding to 31106640 its reverse (4660113), we get a palindrome (35766753).

The spelling of 31106640 in words is "thirty-one million, one hundred six thousand, six hundred forty".