78724406 has 4 divisors (see below), whose sum is σ = 118086612. Its totient is φ = 39362202.

The previous prime is 78724361. The next prime is 78724411. The reversal of 78724406 is 60442787.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 78724406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19681100 + ... + 19681103.

It is an arithmetic number, because the mean of its divisors is an integer number (29521653).

Almost surely, 2^78724406 is an apocalyptic number.

78724406 is a deficient number, since it is larger than the sum of its proper divisors (39362206).

78724406 is a wasteful number, since it uses less digits than its factorization.

78724406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39362205.

The product of its (nonzero) digits is 75264, while the sum is 38.

The square root of 78724406 is about 8872.6774989289. The cubic root of 78724406 is about 428.5845036117.

The spelling of 78724406 in words is "seventy-eight million, seven hundred twenty-four thousand, four hundred six".