77091640 has 32 divisors (see below), whose sum is σ = 173954880. Its totient is φ = 30748032.

The previous prime is 77091629. The next prime is 77091649. The reversal of 77091640 is 4619077.

It is a junction number, because it is equal to n+sod(n) for n = 77091596 and 77091605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77091649) by changing a digit.

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, 12337 + ... + 17503.

It is an arithmetic number, because the mean of its divisors is an integer number (5436090).

Almost surely, 2^77091640 is an apocalyptic number.

It is an amenable number.

77091640 is an abundant number, since it is smaller than the sum of its proper divisors (96863240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77091640 is a wasteful number, since it uses less digits than its factorization.

77091640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5551 (or 5547 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 34.

The square root of 77091640 is about 8780.1845083119. The cubic root of 77091640 is about 425.6007927464.

The spelling of 77091640 in words is "seventy-seven million, ninety-one thousand, six hundred forty".