31340520 has 160 divisors (see below), whose sum is σ = 111731400. Its totient is φ = 7852032.

The previous prime is 31340509. The next prime is 31340527. The reversal of 31340520 is 2504313.

It can be written as a sum of positive squares in 4 ways, for example, as 24147396 + 7193124 = 4914^2 + 2682^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 31340493 and 31340502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31340527) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 54796 + ... + 55364.

Almost surely, 2^31340520 is an apocalyptic number.

31340520 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 31340520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55865700).

31340520 is an abundant number, since it is smaller than the sum of its proper divisors (80390880).

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

31340520 is a wasteful number, since it uses less digits than its factorization.

31340520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609 (or 596 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 31340520 is about 5598.2604441023. The cubic root of 31340520 is about 315.2840974379.

Adding to 31340520 its reverse (2504313), we get a palindrome (33844833).

The spelling of 31340520 in words is "thirty-one million, three hundred forty thousand, five hundred twenty".