77727681 has 24 divisors (see below), whose sum is σ = 117621504. Its totient is φ = 51289200.

The previous prime is 77727673. The next prime is 77727697. The reversal of 77727681 is 18672777.

It is a happy number.

It is not a de Polignac number, because 77727681 - 2³ = 77727673 is a prime.

It is a super-2 number, since 2×77727681² = 12083184787275522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77727631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22960 + ... + 26126.

It is an arithmetic number, because the mean of its divisors is an integer number (4900896).

Almost surely, 2^77727681 is an apocalyptic number.

It is an amenable number.

77727681 is a deficient number, since it is larger than the sum of its proper divisors (39893823).

77727681 is a wasteful number, since it uses less digits than its factorization.

77727681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3283 (or 3271 counting only the distinct ones).

The product of its digits is 230496, while the sum is 45.

The square root of 77727681 is about 8816.3303590553. The cubic root of 77727681 is about 426.7680549933.

The spelling of 77727681 in words is "seventy-seven million, seven hundred twenty-seven thousand, six hundred eighty-one".