77867849 has 2 divisors, whose sum is σ = 77867850. Its totient is φ = 77867848.

The previous prime is 77867843. The next prime is 77867887. The reversal of 77867849 is 94876877.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76877824 + 990025 = 8768^2 + 995^2 .

It is a cyclic number.

It is not a de Polignac number, because 77867849 - 2⁸ = 77867593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77867794 and 77867803.

It is not a weakly prime, because it can be changed into another prime (77867843) 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 as a sum of consecutive naturals, namely, 38933924 + 38933925.

It is an arithmetic number, because the mean of its divisors is an integer number (38933925).

Almost surely, 2^77867849 is an apocalyptic number.

It is an amenable number.

77867849 is a deficient number, since it is larger than the sum of its proper divisors (1).

77867849 is an equidigital number, since it uses as much as digits as its factorization.

77867849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4741632, while the sum is 56.

The square root of 77867849 is about 8824.2761176201. The cubic root of 77867849 is about 427.0244342831.

Subtracting 77867849 from its reverse (94876877), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 77867849 in words is "seventy-seven million, eight hundred sixty-seven thousand, eight hundred forty-nine".