78379917 has 16 divisors (see below), whose sum is σ = 130294272. Its totient is φ = 40716720.

The previous prime is 78379913. The next prime is 78379919. The reversal of 78379917 is 71997387.

It is a happy number.

It is not a de Polignac number, because 78379917 - 2² = 78379913 is a prime.

It is a super-2 number, since 2×78379917² = 12286822777853778, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78379917.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78379913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169423 + ... + 169884.

It is an arithmetic number, because the mean of its divisors is an integer number (8143392).

Almost surely, 2^78379917 is an apocalyptic number.

78379917 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

It is an amenable number.

78379917 is a deficient number, since it is larger than the sum of its proper divisors (51914355).

78379917 is a wasteful number, since it uses less digits than its factorization.

78379917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339328.

The product of its digits is 666792, while the sum is 51.

The square root of 78379917 is about 8853.2433040101. The cubic root of 78379917 is about 427.9584439375.

The spelling of 78379917 in words is "seventy-eight million, three hundred seventy-nine thousand, nine hundred seventeen".