77842987 has 4 divisors (see below), whose sum is σ = 78146136. Its totient is φ = 77539840.

The previous prime is 77842979. The next prime is 77842993. The reversal of 77842987 is 78924877.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 77842987 - 2³ = 77842979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77842927) 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, 151189 + ... + 151702.

It is an arithmetic number, because the mean of its divisors is an integer number (19536534).

Almost surely, 2^77842987 is an apocalyptic number.

77842987 is a deficient number, since it is larger than the sum of its proper divisors (303149).

77842987 is a wasteful number, since it uses less digits than its factorization.

77842987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303148.

The product of its digits is 1580544, while the sum is 52.

The square root of 77842987 is about 8822.8672777051. The cubic root of 77842987 is about 426.9789820126.

The spelling of 77842987 in words is "seventy-seven million, eight hundred forty-two thousand, nine hundred eighty-seven".