77091840 has 264 divisors, whose sum is σ = 306558720. Its totient is φ = 17547264.

The previous prime is 77091827. The next prime is 77091841. The reversal of 77091840 is 4819077.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 77091795 and 77091804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77091841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 322441 + ... + 322679.

Almost surely, 2^77091840 is an apocalyptic number.

77091840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77091840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153279360).

77091840 is an abundant number, since it is smaller than the sum of its proper divisors (229466880).

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

77091840 is a wasteful number, since it uses less digits than its factorization.

77091840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 77091840 is about 8780.1958975868. The cubic root of 77091840 is about 425.6011607936.

The spelling of 77091840 in words is "seventy-seven million, ninety-one thousand, eight hundred forty".