77891712 has 64 divisors (see below), whose sum is σ = 208169760. Its totient is φ = 25804800.

The previous prime is 77891711. The next prime is 77891717. The reversal of 77891712 is 21719877.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (77891711) 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 7 ways as a sum of consecutive naturals, for example, 73587 + ... + 74637.

Almost surely, 2^77891712 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 77891712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104084880).

77891712 is an abundant number, since it is smaller than the sum of its proper divisors (130278048).

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

77891712 is a wasteful number, since it uses less digits than its factorization.

77891712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1261 (or 1249 counting only the distinct ones).

The product of its digits is 49392, while the sum is 42.

The square root of 77891712 is about 8825.6281362858. The cubic root of 77891712 is about 427.0680511007.

The spelling of 77891712 in words is "seventy-seven million, eight hundred ninety-one thousand, seven hundred twelve".