77985949 has 4 divisors (see below), whose sum is σ = 79457436. Its totient is φ = 76514464.

The previous prime is 77985907. The next prime is 77985967. The reversal of 77985949 is 94958977.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 71825625 + 6160324 = 8475^2 + 2482^2 .

It is a cyclic number.

It is not a de Polignac number, because 77985949 - 2¹⁷ = 77854877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77985893 and 77985902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77985979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 735664 + ... + 735769.

It is an arithmetic number, because the mean of its divisors is an integer number (19864359).

Almost surely, 2^77985949 is an apocalyptic number.

It is an amenable number.

77985949 is a deficient number, since it is larger than the sum of its proper divisors (1471487).

77985949 is a wasteful number, since it uses less digits than its factorization.

77985949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1471486.

The product of its digits is 5715360, while the sum is 58.

The square root of 77985949 is about 8830.9653492696. The cubic root of 77985949 is about 427.2402105918.

The spelling of 77985949 in words is "seventy-seven million, nine hundred eighty-five thousand, nine hundred forty-nine".