77181985 has 8 divisors (see below), whose sum is σ = 93209256. Its totient is φ = 61351680.

The previous prime is 77181953. The next prime is 77182013. The reversal of 77181985 is 58918177.

It can be written as a sum of positive squares in 4 ways, for example, as 16451136 + 60730849 = 4056^2 + 7793^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 77181985 - 2⁵ = 77181953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48376 + ... + 49945.

It is an arithmetic number, because the mean of its divisors is an integer number (11651157).

Almost surely, 2^77181985 is an apocalyptic number.

It is an amenable number.

77181985 is a deficient number, since it is larger than the sum of its proper divisors (16027271).

77181985 is a wasteful number, since it uses less digits than its factorization.

77181985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98483.

The product of its digits is 141120, while the sum is 46.

The square root of 77181985 is about 8785.3278254144. The cubic root of 77181985 is about 425.7669841041.

The spelling of 77181985 in words is "seventy-seven million, one hundred eighty-one thousand, nine hundred eighty-five".