78409688 has 16 divisors (see below), whose sum is σ = 168020880. Its totient is φ = 33604128.

The previous prime is 78409663. The next prime is 78409693. The reversal of 78409688 is 88690487.

It is a super-2 number, since 2×78409688² = 12296158344514688, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700031 + ... + 700142.

It is an arithmetic number, because the mean of its divisors is an integer number (10501305).

Almost surely, 2^78409688 is an apocalyptic number.

It is an amenable number.

78409688 is an abundant number, since it is smaller than the sum of its proper divisors (89611192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78409688 is a wasteful number, since it uses less digits than its factorization.

78409688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400186 (or 1400182 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 50.

The square root of 78409688 is about 8854.9245056070. The cubic root of 78409688 is about 428.0126208175.

It can be divided in two parts, 78409 and 688, that added together give a palindrome (79097).

The spelling of 78409688 in words is "seventy-eight million, four hundred nine thousand, six hundred eighty-eight".