78909773 has 6 divisors (see below), whose sum is σ = 80789454. Its totient is φ = 77072856.

The previous prime is 78909769. The next prime is 78909781. The reversal of 78909773 is 37790987.

It can be written as a sum of positive squares in only one way, i.e., 69588964 + 9320809 = 8342^2 + 3053^2 .

It is not a de Polignac number, because 78909773 - 2² = 78909769 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78909763) 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 in 5 ways as a sum of consecutive naturals, for example, 19490 + ... + 23187.

It is an arithmetic number, because the mean of its divisors is an integer number (13464909).

Almost surely, 2^78909773 is an apocalyptic number.

It is an amenable number.

78909773 is a deficient number, since it is larger than the sum of its proper divisors (1879681).

78909773 is an equidigital number, since it uses as much as digits as its factorization.

78909773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42763 (or 42720 counting only the distinct ones).

The product of its (nonzero) digits is 666792, while the sum is 50.

The square root of 78909773 is about 8883.1173019385. The cubic root of 78909773 is about 428.9206261868.

The spelling of 78909773 in words is "seventy-eight million, nine hundred nine thousand, seven hundred seventy-three".