131205406 has 4 divisors (see below), whose sum is σ = 196808112. Its totient is φ = 65602702.

The previous prime is 131205391. The next prime is 131205419. The reversal of 131205406 is 604502131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 604502131 = 61 ⋅9909871.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32801350 + ... + 32801353.

It is an arithmetic number, because the mean of its divisors is an integer number (49202028).

Almost surely, 2^131205406 is an apocalyptic number.

131205406 is a deficient number, since it is larger than the sum of its proper divisors (65602706).

131205406 is an equidigital number, since it uses as much as digits as its factorization.

131205406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65602705.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 131205406 is about 11454.4928303264. The cubic root of 131205406 is about 508.1406161047.

Adding to 131205406 its reverse (604502131), we get a palindrome (735707537).

The spelling of 131205406 in words is "one hundred thirty-one million, two hundred five thousand, four hundred six".