31404340 has 72 divisors (see below), whose sum is σ = 76416480. Its totient is φ = 10802880.

The previous prime is 31404337. The next prime is 31404341. The reversal of 31404340 is 4340413.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31404341) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45639 + ... + 46321.

It is an arithmetic number, because the mean of its divisors is an integer number (1061340).

Almost surely, 2^31404340 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 31404340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38208240).

31404340 is an abundant number, since it is smaller than the sum of its proper divisors (45012140).

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

31404340 is a wasteful number, since it uses less digits than its factorization.

31404340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 733 (or 720 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 31404340 is about 5603.9575301745. The cubic root of 31404340 is about 315.4979610294.

Adding to 31404340 its reverse (4340413), we get a palindrome (35744753).

The spelling of 31404340 in words is "thirty-one million, four hundred four thousand, three hundred forty".