77366021 has 2 divisors, whose sum is σ = 77366022. Its totient is φ = 77366020.

The previous prime is 77366017. The next prime is 77366027. The reversal of 77366021 is 12066377.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77193796 + 172225 = 8786^2 + 415^2 .

It is an emirp because it is prime and its reverse (12066377) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77366021 - 2² = 77366017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77366027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38683010 + 38683011.

It is an arithmetic number, because the mean of its divisors is an integer number (38683011).

Almost surely, 2^77366021 is an apocalyptic number.

It is an amenable number.

77366021 is a deficient number, since it is larger than the sum of its proper divisors (1).

77366021 is an equidigital number, since it uses as much as digits as its factorization.

77366021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 77366021 is about 8795.7956433742. The cubic root of 77366021 is about 426.1051211113.

The spelling of 77366021 in words is "seventy-seven million, three hundred sixty-six thousand, twenty-one".