78442807 has 4 divisors (see below), whose sum is σ = 79517440. Its totient is φ = 77368176.

The previous prime is 78442783. The next prime is 78442817. The reversal of 78442807 is 70824487.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78442807 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78442807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78442817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 537207 + ... + 537352.

It is an arithmetic number, because the mean of its divisors is an integer number (19879360).

Almost surely, 2^78442807 is an apocalyptic number.

78442807 is a deficient number, since it is larger than the sum of its proper divisors (1074633).

78442807 is a wasteful number, since it uses less digits than its factorization.

78442807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1074632.

The product of its (nonzero) digits is 100352, while the sum is 40.

The square root of 78442807 is about 8856.7943975233. The cubic root of 78442807 is about 428.0728742334.

It can be divided in two parts, 7844280 and 7, that multiplied together give a triangular number (54909960 = T₁₀₄₇₉).

The spelling of 78442807 in words is "seventy-eight million, four hundred forty-two thousand, eight hundred seven".