77640911 has 4 divisors (see below), whose sum is σ = 79739352. Its totient is φ = 75542472.

The previous prime is 77640889. The next prime is 77640931. The reversal of 77640911 is 11904677.

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 77640911 - 2²⁶ = 10532047 is a prime.

It is a super-2 number, since 2×77640911² = 12056222121819842, 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 (77640931) 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, 1049165 + ... + 1049238.

It is an arithmetic number, because the mean of its divisors is an integer number (19934838).

Almost surely, 2^77640911 is an apocalyptic number.

77640911 is a deficient number, since it is larger than the sum of its proper divisors (2098441).

77640911 is a wasteful number, since it uses less digits than its factorization.

77640911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2098440.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 77640911 is about 8811.4080032649. The cubic root of 77640911 is about 426.6091907306.

The spelling of 77640911 in words is "seventy-seven million, six hundred forty thousand, nine hundred eleven".