77725148209 has 2 divisors, whose sum is σ = 77725148210. Its totient is φ = 77725148208.

The previous prime is 77725148201. The next prime is 77725148309. The reversal of 77725148209 is 90284152777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72641030400 + 5084117809 = 269520^2 + 71303^2 .

It is a cyclic number.

It is not a de Polignac number, because 77725148209 - 2³ = 77725148201 is a prime.

It is a super-2 number, since 2×77725148209² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (77725148201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38862574104 + 38862574105.

It is an arithmetic number, because the mean of its divisors is an integer number (38862574105).

Almost surely, 2^77725148209 is an apocalyptic number.

It is an amenable number.

77725148209 is a deficient number, since it is larger than the sum of its proper divisors (1).

77725148209 is an equidigital number, since it uses as much as digits as its factorization.

77725148209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1975680, while the sum is 52.

The spelling of 77725148209 in words is "seventy-seven billion, seven hundred twenty-five million, one hundred forty-eight thousand, two hundred nine".