77681239 has 4 divisors (see below), whose sum is σ = 77730840. Its totient is φ = 77631640.

The previous prime is 77681231. The next prime is 77681249. The reversal of 77681239 is 93218677.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93218677 = 3769 ⋅24733.

It is a cyclic number.

It is not a de Polignac number, because 77681239 - 2³ = 77681231 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77681195 and 77681204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77681231) 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, 22372 + ... + 25609.

It is an arithmetic number, because the mean of its divisors is an integer number (19432710).

Almost surely, 2^77681239 is an apocalyptic number.

77681239 is a deficient number, since it is larger than the sum of its proper divisors (49601).

77681239 is a wasteful number, since it uses less digits than its factorization.

77681239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49600.

The product of its digits is 127008, while the sum is 43.

The square root of 77681239 is about 8813.6961032248. The cubic root of 77681239 is about 426.6830406178.

The spelling of 77681239 in words is "seventy-seven million, six hundred eighty-one thousand, two hundred thirty-nine".