77658949 has 4 divisors (see below), whose sum is σ = 78180300. Its totient is φ = 77137600.

The previous prime is 77658943. The next prime is 77658979. The reversal of 77658949 is 94985677.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94985677 = 4241 ⋅22397.

It can be written as a sum of positive squares in 2 ways, for example, as 10304100 + 67354849 = 3210^2 + 8207^2 .

It is a cyclic number.

It is not a de Polignac number, because 77658949 - 2⁷ = 77658821 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77658949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77658943) 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, 260452 + ... + 260749.

It is an arithmetic number, because the mean of its divisors is an integer number (19545075).

Almost surely, 2^77658949 is an apocalyptic number.

It is an amenable number.

77658949 is a deficient number, since it is larger than the sum of its proper divisors (521351).

77658949 is a wasteful number, since it uses less digits than its factorization.

77658949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521350.

The product of its digits is 3810240, while the sum is 55.

The square root of 77658949 is about 8812.4315032799. The cubic root of 77658949 is about 426.6422256372.

The spelling of 77658949 in words is "seventy-seven million, six hundred fifty-eight thousand, nine hundred forty-nine".