77281344 has 112 divisors (see below), whose sum is σ = 259689600. Its totient is φ = 22076928.

The previous prime is 77281339. The next prime is 77281361. The reversal of 77281344 is 44318277.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×77281344² = 11944812260892672, which contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 77281299 and 77281308.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8902 + ... + 15290.

Almost surely, 2^77281344 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 77281344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129844800).

77281344 is an abundant number, since it is smaller than the sum of its proper divisors (182408256).

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

77281344 is a wasteful number, since it uses less digits than its factorization.

77281344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6417 (or 6401 counting only the distinct ones).

The product of its digits is 37632, while the sum is 36.

The square root of 77281344 is about 8790.9808326489. The cubic root of 77281344 is about 425.9496072111.

The spelling of 77281344 in words is "seventy-seven million, two hundred eighty-one thousand, three hundred forty-four".