31531142 has 4 divisors (see below), whose sum is σ = 47296716. Its totient is φ = 15765570.

The previous prime is 31531139. The next prime is 31531163. The reversal of 31531142 is 24113513.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7882784 + ... + 7882787.

It is an arithmetic number, because the mean of its divisors is an integer number (11824179).

Almost surely, 2^31531142 is an apocalyptic number.

31531142 is a deficient number, since it is larger than the sum of its proper divisors (15765574).

31531142 is a wasteful number, since it uses less digits than its factorization.

31531142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15765573.

The product of its digits is 360, while the sum is 20.

The square root of 31531142 is about 5615.2597446601. The cubic root of 31531142 is about 315.9220218317.

Adding to 31531142 its reverse (24113513), we get a palindrome (55644655).

The spelling of 31531142 in words is "thirty-one million, five hundred thirty-one thousand, one hundred forty-two".