131731428 has 12 divisors (see below), whose sum is σ = 307373360. Its totient is φ = 43910472.

The previous prime is 131731423. The next prime is 131731451. The reversal of 131731428 is 824137131.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 131731395 and 131731404.

It is not an unprimeable number, because it can be changed into a prime (131731423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5488798 + ... + 5488821.

Almost surely, 2^131731428 is an apocalyptic number.

It is an amenable number.

131731428 is an abundant number, since it is smaller than the sum of its proper divisors (175641932).

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

131731428 is a wasteful number, since it uses less digits than its factorization.

131731428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10977626 (or 10977624 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 131731428 is about 11477.4312457100. The cubic root of 131731428 is about 508.8187810747.

Adding to 131731428 its reverse (824137131), we get a palindrome (955868559).

The spelling of 131731428 in words is "one hundred thirty-one million, seven hundred thirty-one thousand, four hundred twenty-eight".