78642215 has 8 divisors (see below), whose sum is σ = 94537680. Its totient is φ = 62802432.

The previous prime is 78642211. The next prime is 78642241. The reversal of 78642215 is 51224687.

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 78642215 - 2² = 78642211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78642211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10745 + ... + 16514.

It is an arithmetic number, because the mean of its divisors is an integer number (11817210).

Almost surely, 2^78642215 is an apocalyptic number.

78642215 is a deficient number, since it is larger than the sum of its proper divisors (15895465).

78642215 is a wasteful number, since it uses less digits than its factorization.

78642215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27841.

The product of its digits is 26880, while the sum is 35.

The square root of 78642215 is about 8868.0445984445. The cubic root of 78642215 is about 428.4352993313.

The spelling of 78642215 in words is "seventy-eight million, six hundred forty-two thousand, two hundred fifteen".