77825281 has 2 divisors, whose sum is σ = 77825282. Its totient is φ = 77825280.

The previous prime is 77825263. The next prime is 77825287. The reversal of 77825281 is 18252877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69872881 + 7952400 = 8359^2 + 2820^2 .

It is a cyclic number.

It is not a de Polignac number, because 77825281 - 2¹¹ = 77823233 is a prime.

It is a super-2 number, since 2×77825281² = 12113548725457922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (77825287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38912640 + 38912641.

It is an arithmetic number, because the mean of its divisors is an integer number (38912641).

Almost surely, 2^77825281 is an apocalyptic number.

It is an amenable number.

77825281 is a deficient number, since it is larger than the sum of its proper divisors (1).

77825281 is an equidigital number, since it uses as much as digits as its factorization.

77825281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62720, while the sum is 40.

The square root of 77825281 is about 8821.8638053418. The cubic root of 77825281 is about 426.9466063145.

The spelling of 77825281 in words is "seventy-seven million, eight hundred twenty-five thousand, two hundred eighty-one".