77747081 has 4 divisors (see below), whose sum is σ = 77831700. Its totient is φ = 77662464.

The previous prime is 77747063. The next prime is 77747093. The reversal of 77747081 is 18074777.

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 28185481 + 49561600 = 5309^2 + 7040^2 .

It is a cyclic number.

It is not a de Polignac number, because 77747081 - 2¹⁸ = 77484937 is a prime.

It is a super-2 number, since 2×77747081² = 12089217208041122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77747281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40916 + ... + 42773.

It is an arithmetic number, because the mean of its divisors is an integer number (19457925).

Almost surely, 2^77747081 is an apocalyptic number.

It is an amenable number.

77747081 is a deficient number, since it is larger than the sum of its proper divisors (84619).

77747081 is an equidigital number, since it uses as much as digits as its factorization.

77747081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84618.

The product of its (nonzero) digits is 76832, while the sum is 41.

The square root of 77747081 is about 8817.4305214161. The cubic root of 77747081 is about 426.8035576244.

The spelling of 77747081 in words is "seventy-seven million, seven hundred forty-seven thousand, eighty-one".