78008721 has 8 divisors (see below), whose sum is σ = 118870464. Its totient is φ = 44576400.

The previous prime is 78008719. The next prime is 78008731. The reversal of 78008721 is 12780087.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78008721 - 2¹ = 78008719 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (78008731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1857330 + ... + 1857371.

It is an arithmetic number, because the mean of its divisors is an integer number (14858808).

Almost surely, 2^78008721 is an apocalyptic number.

It is an amenable number.

78008721 is a deficient number, since it is larger than the sum of its proper divisors (40861743).

78008721 is a wasteful number, since it uses less digits than its factorization.

78008721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3714711.

The product of its (nonzero) digits is 6272, while the sum is 33.

The square root of 78008721 is about 8832.2545819287. The cubic root of 78008721 is about 427.2817914466.

The spelling of 78008721 in words is "seventy-eight million, eight thousand, seven hundred twenty-one".