31130505 has 48 divisors (see below), whose sum is σ = 63358464. Its totient is φ = 13841280.

The previous prime is 31130461. The next prime is 31130507. The reversal of 31130505 is 50503113.

It is a happy number.

31130505 is a `hidden beast` number, since 31 + 130 + 505 = 666.

It is not a de Polignac number, because 31130505 - 2⁶ = 31130441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31130507) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10320 + ... + 12990.

It is an arithmetic number, because the mean of its divisors is an integer number (1319968).

Almost surely, 2^31130505 is an apocalyptic number.

31130505 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31130505 is an abundant number, since it is smaller than the sum of its proper divisors (32227959).

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

31130505 is a wasteful number, since it uses less digits than its factorization.

31130505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2726 (or 2723 counting only the distinct ones).

The product of its (nonzero) digits is 225, while the sum is 18.

The square root of 31130505 is about 5579.4717491892. The cubic root of 31130505 is about 314.5782716123.

Adding to 31130505 its reverse (50503113), we get a palindrome (81633618).

The spelling of 31130505 in words is "thirty-one million, one hundred thirty thousand, five hundred five".