77689121 has 2 divisors, whose sum is σ = 77689122. Its totient is φ = 77689120.

The previous prime is 77689111. The next prime is 77689151. The reversal of 77689121 is 12198677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75498721 + 2190400 = 8689^2 + 1480^2 .

It is an emirp because it is prime and its reverse (12198677) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77689121 - 2²⁶ = 10580257 is a prime.

It is not a weakly prime, because it can be changed into another prime (77689111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38844560 + 38844561.

It is an arithmetic number, because the mean of its divisors is an integer number (38844561).

Almost surely, 2^77689121 is an apocalyptic number.

It is an amenable number.

77689121 is a deficient number, since it is larger than the sum of its proper divisors (1).

77689121 is an equidigital number, since it uses as much as digits as its factorization.

77689121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 41.

The square root of 77689121 is about 8814.1432368665. The cubic root of 77689121 is about 426.6974713951.

The spelling of 77689121 in words is "seventy-seven million, six hundred eighty-nine thousand, one hundred twenty-one".