31432140 has 144 divisors (see below), whose sum is σ = 101477376. Its totient is φ = 7862400.

The previous prime is 31432111. The next prime is 31432153. The reversal of 31432140 is 4123413.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 239875 + ... + 240005.

It is an arithmetic number, because the mean of its divisors is an integer number (704704).

Almost surely, 2^31432140 is an apocalyptic number.

31432140 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 31432140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50738688).

31432140 is an abundant number, since it is smaller than the sum of its proper divisors (70045236).

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

31432140 is a wasteful number, since it uses less digits than its factorization.

31432140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 31432140 is about 5606.4373714508. The cubic root of 31432140 is about 315.5910294452.

Adding to 31432140 its reverse (4123413), we get a palindrome (35555553).

The spelling of 31432140 in words is "thirty-one million, four hundred thirty-two thousand, one hundred forty".