77343821 has 2 divisors, whose sum is σ = 77343822. Its totient is φ = 77343820.

The previous prime is 77343817. The next prime is 77343839. The reversal of 77343821 is 12834377.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48302500 + 29041321 = 6950^2 + 5389^2 .

It is an emirp because it is prime and its reverse (12834377) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77343821 - 2² = 77343817 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77342821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38671910 + 38671911.

It is an arithmetic number, because the mean of its divisors is an integer number (38671911).

Almost surely, 2^77343821 is an apocalyptic number.

It is an amenable number.

77343821 is a deficient number, since it is larger than the sum of its proper divisors (1).

77343821 is an equidigital number, since it uses as much as digits as its factorization.

77343821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 35.

The square root of 77343821 is about 8794.5335862682. The cubic root of 77343821 is about 426.0643605874.

The spelling of 77343821 in words is "seventy-seven million, three hundred forty-three thousand, eight hundred twenty-one".