77109987 has 4 divisors (see below), whose sum is σ = 102813320. Its totient is φ = 51406656.

The previous prime is 77109959. The next prime is 77110001. The reversal of 77109987 is 78990177.

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

It is not a de Polignac number, because 77109987 - 2¹⁸ = 76847843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77159987) 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, 12851662 + ... + 12851667.

It is an arithmetic number, because the mean of its divisors is an integer number (25703330).

Almost surely, 2^77109987 is an apocalyptic number.

77109987 is a deficient number, since it is larger than the sum of its proper divisors (25703333).

77109987 is a wasteful number, since it uses less digits than its factorization.

77109987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25703332.

The product of its (nonzero) digits is 222264, while the sum is 48.

The square root of 77109987 is about 8781.2292419683. The cubic root of 77109987 is about 425.6345529067.

The spelling of 77109987 in words is "seventy-seven million, one hundred nine thousand, nine hundred eighty-seven".