77773649 has 4 divisors (see below), whose sum is σ = 81155136. Its totient is φ = 74392164.

The previous prime is 77773643. The next prime is 77773681. The reversal of 77773649 is 94637777.

It is a happy number.

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: 94637777 = 13 ⋅7279829.

It is a cyclic number.

It is not a de Polignac number, because 77773649 - 2¹² = 77769553 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77773597 and 77773606.

It is not an unprimeable number, because it can be changed into a prime (77773643) 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, 1690709 + ... + 1690754.

It is an arithmetic number, because the mean of its divisors is an integer number (20288784).

Almost surely, 2^77773649 is an apocalyptic number.

It is an amenable number.

77773649 is a deficient number, since it is larger than the sum of its proper divisors (3381487).

77773649 is a wasteful number, since it uses less digits than its factorization.

77773649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3381486.

The product of its digits is 1555848, while the sum is 50.

The square root of 77773649 is about 8818.9369540779. The cubic root of 77773649 is about 426.8521683477.

The spelling of 77773649 in words is "seventy-seven million, seven hundred seventy-three thousand, six hundred forty-nine".