78131405 has 16 divisors (see below), whose sum is σ = 108298944. Its totient is φ = 53479680.

The previous prime is 78131393. The next prime is 78131407. The reversal of 78131405 is 50413187.

It is not a de Polignac number, because 78131405 - 2⁸ = 78131149 is a prime.

It is a super-2 number, since 2×78131405² = 12209032894548050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78131407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40847 + ... + 42716.

It is an arithmetic number, because the mean of its divisors is an integer number (6768684).

Almost surely, 2^78131405 is an apocalyptic number.

It is an amenable number.

78131405 is a deficient number, since it is larger than the sum of its proper divisors (30167539).

78131405 is a wasteful number, since it uses less digits than its factorization.

78131405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83596.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 78131405 is about 8839.1970789207. The cubic root of 78131405 is about 427.5056689056.

The spelling of 78131405 in words is "seventy-eight million, one hundred thirty-one thousand, four hundred five".