78772005 has 72 divisors (see below), whose sum is σ = 155603448. Its totient is φ = 36640512.

The previous prime is 78771989. The next prime is 78772007. The reversal of 78772005 is 50027787.

It can be written as a sum of positive squares in 4 ways, for example, as 1718721 + 77053284 = 1311^2 + 8778^2 .

It is not a de Polignac number, because 78772005 - 2⁴ = 78771989 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78772007) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 210999 + ... + 211371.

It is an arithmetic number, because the mean of its divisors is an integer number (2161159).

Almost surely, 2^78772005 is an apocalyptic number.

It is an amenable number.

78772005 is a deficient number, since it is larger than the sum of its proper divisors (76831443).

78772005 is a wasteful number, since it uses less digits than its factorization.

78772005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 27440, while the sum is 36.

The square root of 78772005 is about 8875.3594293414. The cubic root of 78772005 is about 428.6708643084.

The spelling of 78772005 in words is "seventy-eight million, seven hundred seventy-two thousand, five".