78820487 has 4 divisors (see below), whose sum is σ = 80307720. Its totient is φ = 77333256.

The previous prime is 78820477. The next prime is 78820537. The reversal of 78820487 is 78402887.

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-78820487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78820477) 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 3 ways as a sum of consecutive naturals, for example, 743537 + ... + 743642.

It is an arithmetic number, because the mean of its divisors is an integer number (20076930).

Almost surely, 2^78820487 is an apocalyptic number.

78820487 is a deficient number, since it is larger than the sum of its proper divisors (1487233).

78820487 is a wasteful number, since it uses less digits than its factorization.

78820487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1487232.

The product of its (nonzero) digits is 200704, while the sum is 44.

The square root of 78820487 is about 8878.0902788832. The cubic root of 78820487 is about 428.7587913097.

The spelling of 78820487 in words is "seventy-eight million, eight hundred twenty thousand, four hundred eighty-seven".