31231380 has 96 divisors (see below), whose sum is σ = 94179456. Its totient is φ = 7704576.

The previous prime is 31231379. The next prime is 31231391. The reversal of 31231380 is 8313213.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68112 + ... + 68568.

It is an arithmetic number, because the mean of its divisors is an integer number (981036).

Almost surely, 2^31231380 is an apocalyptic number.

31231380 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 31231380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47089728).

31231380 is an abundant number, since it is smaller than the sum of its proper divisors (62948076).

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

31231380 is a wasteful number, since it uses less digits than its factorization.

31231380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553 (or 551 counting only the distinct ones).

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

The square root of 31231380 is about 5588.5042721644. The cubic root of 31231380 is about 314.9176907646.

Adding to 31231380 its reverse (8313213), we get a palindrome (39544593).

The spelling of 31231380 in words is "thirty-one million, two hundred thirty-one thousand, three hundred eighty".