31031406 has 72 divisors (see below), whose sum is σ = 79067664. Its totient is φ = 8769600.

The previous prime is 31031369. The next prime is 31031431. The reversal of 31031406 is 60413013.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 133066 + ... + 133298.

It is an arithmetic number, because the mean of its divisors is an integer number (1098162).

Almost surely, 2^31031406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31031406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39533832).

31031406 is an abundant number, since it is smaller than the sum of its proper divisors (48036258).

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

31031406 is a wasteful number, since it uses less digits than its factorization.

31031406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 31031406 is about 5570.5839909295. The cubic root of 31031406 is about 314.2441135217.

Adding to 31031406 its reverse (60413013), we get a palindrome (91444419).

The spelling of 31031406 in words is "thirty-one million, thirty-one thousand, four hundred six".