78399429 has 4 divisors (see below), whose sum is σ = 104532576. Its totient is φ = 52266284.

The previous prime is 78399401. The next prime is 78399437. The reversal of 78399429 is 92499387.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 92499387 = 3 ⋅30833129.

It is a cyclic number.

It is not a de Polignac number, because 78399429 - 2⁵ = 78399397 is a prime.

It is a super-2 number, since 2×78399429² = 12292940935052082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78399229) 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, 13066569 + ... + 13066574.

It is an arithmetic number, because the mean of its divisors is an integer number (26133144).

Almost surely, 2^78399429 is an apocalyptic number.

It is an amenable number.

78399429 is a deficient number, since it is larger than the sum of its proper divisors (26133147).

78399429 is a wasteful number, since it uses less digits than its factorization.

78399429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26133146.

The product of its digits is 979776, while the sum is 51.

The square root of 78399429 is about 8854.3452044745. The cubic root of 78399429 is about 427.9939531710.

The spelling of 78399429 in words is "seventy-eight million, three hundred ninety-nine thousand, four hundred twenty-nine".