131216405 has 16 divisors (see below), whose sum is σ = 160273344. Its totient is φ = 103109760.

The previous prime is 131216399. The next prime is 131216419. The reversal of 131216405 is 504612131.

It is not a de Polignac number, because 131216405 - 2²⁶ = 64107541 is a prime.

It is a super-2 number, since 2×131216405² = 34435489882248050, which contains 22 as substring.

It is a Duffinian number.

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 in 15 ways as a sum of consecutive naturals, for example, 111470 + ... + 112640.

It is an arithmetic number, because the mean of its divisors is an integer number (10017084).

Almost surely, 2^131216405 is an apocalyptic number.

It is an amenable number.

131216405 is a deficient number, since it is larger than the sum of its proper divisors (29056939).

131216405 is a wasteful number, since it uses less digits than its factorization.

131216405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1556.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 131216405 is about 11454.9729375499. The cubic root of 131216405 is about 508.1548149162.

Adding to 131216405 its reverse (504612131), we get a palindrome (635828536).

The spelling of 131216405 in words is "one hundred thirty-one million, two hundred sixteen thousand, four hundred five".