31581342 has 72 divisors (see below), whose sum is σ = 78447096. Its totient is φ = 9126144.

The previous prime is 31581337. The next prime is 31581367. The reversal of 31581342 is 24318513.

It is a happy number.

31581342 is a `hidden beast` number, since 315 + 8 + 1 + 342 = 666.

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, 67393 + ... + 67859.

It is an arithmetic number, because the mean of its divisors is an integer number (1089543).

Almost surely, 2^31581342 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31581342, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39223548).

31581342 is an abundant number, since it is smaller than the sum of its proper divisors (46865754).

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

31581342 is a wasteful number, since it uses less digits than its factorization.

31581342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522 (or 502 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 31581342 is about 5619.7279293574. The cubic root of 31581342 is about 316.0895903108.

Adding to 31581342 its reverse (24318513), we get a palindrome (55899855).

The spelling of 31581342 in words is "thirty-one million, five hundred eighty-one thousand, three hundred forty-two".