77281393 has 4 divisors (see below), whose sum is σ = 88321600. Its totient is φ = 66241188.

The previous prime is 77281361. The next prime is 77281409. The reversal of 77281393 is 39318277.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39318277 = 19 ⋅2069383.

It is a cyclic number.

It is not a de Polignac number, because 77281393 - 2⁵ = 77281361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77281313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5520093 + ... + 5520106.

It is an arithmetic number, because the mean of its divisors is an integer number (22080400).

Almost surely, 2^77281393 is an apocalyptic number.

It is an amenable number.

77281393 is a deficient number, since it is larger than the sum of its proper divisors (11040207).

77281393 is a wasteful number, since it uses less digits than its factorization.

77281393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11040206.

The product of its digits is 63504, while the sum is 40.

The square root of 77281393 is about 8790.9836195957. The cubic root of 77281393 is about 425.9496972351.

The spelling of 77281393 in words is "seventy-seven million, two hundred eighty-one thousand, three hundred ninety-three".