131009731 has 4 divisors (see below), whose sum is σ = 137905000. Its totient is φ = 124114464.

The previous prime is 131009707. The next prime is 131009737. The reversal of 131009731 is 137900131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 137900131 = 1319 ⋅104549.

It is a cyclic number.

It is not a de Polignac number, because 131009731 - 2⁵ = 131009699 is a prime.

It is a super-2 number, since 2×131009731² = 34327099233384722, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 131009696 and 131009705.

It is not an unprimeable number, because it can be changed into a prime (131009737) 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, 3447606 + ... + 3447643.

It is an arithmetic number, because the mean of its divisors is an integer number (34476250).

Almost surely, 2^131009731 is an apocalyptic number.

131009731 is a deficient number, since it is larger than the sum of its proper divisors (6895269).

131009731 is an equidigital number, since it uses as much as digits as its factorization.

131009731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6895268.

The product of its (nonzero) digits is 567, while the sum is 25.

The square root of 131009731 is about 11445.9482350743. The cubic root of 131009731 is about 507.8878829081.

Adding to 131009731 its reverse (137900131), we get a palindrome (268909862).

The spelling of 131009731 in words is "one hundred thirty-one million, nine thousand, seven hundred thirty-one".