31330420 has 48 divisors (see below), whose sum is σ = 73156608. Its totient is φ = 11173760.

The previous prime is 31330417. The next prime is 31330421. The reversal of 31330420 is 2403313.

It is a junction number, because it is equal to n+sod(n) for n = 31330394 and 31330403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31330421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10317 + ... + 13003.

It is an arithmetic number, because the mean of its divisors is an integer number (1524096).

Almost surely, 2^31330420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31330420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36578304).

31330420 is an abundant number, since it is smaller than the sum of its proper divisors (41826188).

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

31330420 is a wasteful number, since it uses less digits than its factorization.

31330420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2760 (or 2758 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 31330420 is about 5597.3583054866. The cubic root of 31330420 is about 315.2502252972.

Adding to 31330420 its reverse (2403313), we get a palindrome (33733733).

The spelling of 31330420 in words is "thirty-one million, three hundred thirty thousand, four hundred twenty".