31130100 has 54 divisors (see below), whose sum is σ = 97578390. Its totient is φ = 8301120.

The previous prime is 31130087. The next prime is 31130101. The reversal of 31130100 is 103113.

It can be written as a sum of positive squares in 3 ways, for example, as 527076 + 30603024 = 726^2 + 5532^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31130101) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 16395 + ... + 18194.

Almost surely, 2^31130100 is an apocalyptic number.

31130100 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31130100 is an abundant number, since it is smaller than the sum of its proper divisors (66448290).

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

31130100 is a wasteful number, since it uses less digits than its factorization.

31130100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34609 (or 34599 counting only the distinct ones).

The product of its (nonzero) digits is 9, while the sum is 9.

The square root of 31130100 is about 5579.4354553127. The cubic root of 31130100 is about 314.5769074118.

Adding to 31130100 its reverse (103113), we get a palindrome (31233213).

The spelling of 31130100 in words is "thirty-one million, one hundred thirty thousand, one hundred".