131311021 has 4 divisors (see below), whose sum is σ = 133160544. Its totient is φ = 129461500.

The previous prime is 131311001. The next prime is 131311027. The reversal of 131311021 is 120113131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120113131 = 233 ⋅515507.

It is a cyclic number.

It is not a de Polignac number, because 131311021 - 2⁵ = 131310989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131310992 and 131311010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131311027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 924655 + ... + 924796.

It is an arithmetic number, because the mean of its divisors is an integer number (33290136).

Almost surely, 2^131311021 is an apocalyptic number.

It is an amenable number.

131311021 is a deficient number, since it is larger than the sum of its proper divisors (1849523).

131311021 is an equidigital number, since it uses as much as digits as its factorization.

131311021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1849522.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 131311021 is about 11459.1021026955. The cubic root of 131311021 is about 508.2769236936.

Adding to 131311021 its reverse (120113131), we get a palindrome (251424152).

It can be divided in two parts, 1313110 and 21, that added together give a palindrome (1313131).

The spelling of 131311021 in words is "one hundred thirty-one million, three hundred eleven thousand, twenty-one".