131021243 has 4 divisors (see below), whose sum is σ = 131124648. Its totient is φ = 130917840.

The previous prime is 131021239. The next prime is 131021249. The reversal of 131021243 is 342120131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 342120131 = 263 ⋅1300837.

It is a cyclic number.

It is not a de Polignac number, because 131021243 - 2² = 131021239 is a prime.

It is a super-2 number, since 2×131021243² = 34333132234530098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131021249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49778 + ... + 52343.

It is an arithmetic number, because the mean of its divisors is an integer number (32781162).

Almost surely, 2^131021243 is an apocalyptic number.

131021243 is a deficient number, since it is larger than the sum of its proper divisors (103405).

131021243 is a wasteful number, since it uses less digits than its factorization.

131021243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103404.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 131021243 is about 11446.4511094050. The cubic root of 131021243 is about 507.9027587345.

Adding to 131021243 its reverse (342120131), we get a palindrome (473141374).

The spelling of 131021243 in words is "one hundred thirty-one million, twenty-one thousand, two hundred forty-three".