78161331 has 4 divisors (see below), whose sum is σ = 104215112. Its totient is φ = 52107552.

The previous prime is 78161311. The next prime is 78161341. The reversal of 78161331 is 13316187.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 78161331 - 2⁵ = 78161299 is a prime.

It is a super-2 number, since 2×78161331² = 12218387327383122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78161311) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 13026886 + ... + 13026891.

It is an arithmetic number, because the mean of its divisors is an integer number (26053778).

Almost surely, 2^78161331 is an apocalyptic number.

78161331 is a deficient number, since it is larger than the sum of its proper divisors (26053781).

78161331 is a wasteful number, since it uses less digits than its factorization.

78161331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26053780.

The product of its digits is 3024, while the sum is 30.

The square root of 78161331 is about 8840.8897176698. The cubic root of 78161331 is about 427.5602432115.

The spelling of 78161331 in words is "seventy-eight million, one hundred sixty-one thousand, three hundred thirty-one".