131211405 has 48 divisors (see below), whose sum is σ = 246320256. Its totient is φ = 64229760.

The previous prime is 131211349. The next prime is 131211407. The reversal of 131211405 is 504112131.

It is not a de Polignac number, because 131211405 - 2⁷ = 131211277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131211407) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 122904 + ... + 123966.

It is an arithmetic number, because the mean of its divisors is an integer number (5131672).

Almost surely, 2^131211405 is an apocalyptic number.

131211405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

131211405 is a deficient number, since it is larger than the sum of its proper divisors (115108851).

131211405 is a wasteful number, since it uses less digits than its factorization.

131211405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1298 (or 1295 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 131211405 is about 11454.7546896474. The cubic root of 131211405 is about 508.1483604225.

Adding to 131211405 its reverse (504112131), we get a palindrome (635323536).

The spelling of 131211405 in words is "one hundred thirty-one million, two hundred eleven thousand, four hundred five".