78642286 has 4 divisors (see below), whose sum is σ = 117963432. Its totient is φ = 39321142.

The previous prime is 78642283. The next prime is 78642293. The reversal of 78642286 is 68224687.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68224687 = 19 ⋅3590773.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78642281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19660570 + ... + 19660573.

It is an arithmetic number, because the mean of its divisors is an integer number (29490858).

Almost surely, 2^78642286 is an apocalyptic number.

78642286 is a deficient number, since it is larger than the sum of its proper divisors (39321146).

78642286 is a wasteful number, since it uses less digits than its factorization.

78642286 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39321145.

The product of its digits is 258048, while the sum is 43.

The square root of 78642286 is about 8868.0486015808. The cubic root of 78642286 is about 428.4354282650.

The spelling of 78642286 in words is "seventy-eight million, six hundred forty-two thousand, two hundred eighty-six".