77312 has 20 divisors (see below), whose sum is σ = 155496. Its totient is φ = 38400.

The previous prime is 77291. The next prime is 77317. The reversal of 77312 is 21377.

It is an Ulam number.

It is a nialpdrome in base 5.

It is a zygodrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77317) by changing a digit.

77312 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 437 + ... + 587.

2⁷⁷³¹² 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 77312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77748).

77312 is an abundant number, since it is smaller than the sum of its proper divisors (78184).

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

77312 is an equidigital number, since it uses as much as digits as its factorization.

77312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169 (or 153 counting only the distinct ones).

The product of its digits is 294, while the sum is 20.

The square root of 77312 is about 278.0503551517. The cubic root of 77312 is about 42.6005921729.

Adding to 77312 its reverse (21377), we get a palindrome (98689).

The spelling of 77312 in words is "seventy-seven thousand, three hundred twelve", and thus it is an iban number.