78280765369 has 9 divisors (see below), whose sum is σ = 79800745423. Its totient is φ = 76789220872.

The previous prime is 78280765313. The next prime is 78280765391. The reversal of 78280765369 is 96356708287.

The square root of 78280765369 is 279787.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 56432378025 + 21848387344 = 237555^2 + 147812^2 .

It is not a de Polignac number, because 78280765369 - 2⁹ = 78280764857 is a prime.

It is a super-2 number, since 2×78280765369² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78280765669) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 14826072 + ... + 14831350.

Almost surely, 2^78280765369 is an apocalyptic number.

78280765369 is the 279787-th square number.

78280765369 is the 139894-th centered octagonal number.

It is an amenable number.

78280765369 is a deficient number, since it is larger than the sum of its proper divisors (1519980054).

78280765369 is an frugal number, since it uses more digits than its factorization.

78280765369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10664 (or 5332 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 61.

The spelling of 78280765369 in words is "seventy-eight billion, two hundred eighty million, seven hundred sixty-five thousand, three hundred sixty-nine".