77680181 has 4 divisors (see below), whose sum is σ = 78406272. Its totient is φ = 76954092.

The previous prime is 77680171. The next prime is 77680201. The reversal of 77680181 is 18108677.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18108677 = 47 ⋅385291.

It is a cyclic number.

It is not a de Polignac number, because 77680181 - 2¹⁰ = 77679157 is a prime.

It is a super-2 number, since 2×77680181² = 12068421040385522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77680171) 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, 362885 + ... + 363098.

It is an arithmetic number, because the mean of its divisors is an integer number (19601568).

Almost surely, 2^77680181 is an apocalyptic number.

It is an amenable number.

77680181 is a deficient number, since it is larger than the sum of its proper divisors (726091).

77680181 is a wasteful number, since it uses less digits than its factorization.

77680181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726090.

The product of its (nonzero) digits is 18816, while the sum is 38.

The square root of 77680181 is about 8813.6360827981. The cubic root of 77680181 is about 426.6811035018.

The spelling of 77680181 in words is "seventy-seven million, six hundred eighty thousand, one hundred eighty-one".