77787840 has 224 divisors, whose sum is σ = 278562816. Its totient is φ = 18247680.

The previous prime is 77787839. The next prime is 77787841. The reversal of 77787840 is 4878777.

It is an interprime number because it is at equal distance from previous prime (77787839) and next prime (77787841).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 77787840.

It is not an unprimeable number, because it can be changed into a prime (77787841) 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 31 ways as a sum of consecutive naturals, for example, 286905 + ... + 287175.

It is an arithmetic number, because the mean of its divisors is an integer number (1243584).

Almost surely, 2^77787840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77787840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139281408).

77787840 is an abundant number, since it is smaller than the sum of its proper divisors (200774976).

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

77787840 is a wasteful number, since it uses less digits than its factorization.

77787840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 614656, while the sum is 48.

The square root of 77787840 is about 8819.7414928103. The cubic root of 77787840 is about 426.8781286861.

The spelling of 77787840 in words is "seventy-seven million, seven hundred eighty-seven thousand, eight hundred forty".