78881815 has 8 divisors (see below), whose sum is σ = 94709520. Its totient is φ = 63071232.

The previous prime is 78881813. The next prime is 78881821. The reversal of 78881815 is 51818887.

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

It is a cyclic number.

It is not a de Polignac number, because 78881815 - 2¹ = 78881813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78881813) 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 7 ways as a sum of consecutive naturals, for example, 10512 + ... + 16378.

It is an arithmetic number, because the mean of its divisors is an integer number (11838690).

Almost surely, 2^78881815 is an apocalyptic number.

78881815 is a deficient number, since it is larger than the sum of its proper divisors (15827705).

78881815 is a wasteful number, since it uses less digits than its factorization.

78881815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8561.

The product of its digits is 143360, while the sum is 46.

The square root of 78881815 is about 8881.5435032431. The cubic root of 78881815 is about 428.8699641926.

The spelling of 78881815 in words is "seventy-eight million, eight hundred eighty-one thousand, eight hundred fifteen".