78240361 has 4 divisors (see below), whose sum is σ = 78297300. Its totient is φ = 78183424.

The previous prime is 78240343. The next prime is 78240377. The reversal of 78240361 is 16304287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16304287 = 839 ⋅19433.

It can be written as a sum of positive squares in 2 ways, for example, as 712336 + 77528025 = 844^2 + 8805^2 .

It is a cyclic number.

It is not a de Polignac number, because 78240361 - 2⁵ = 78240329 is a prime.

It is a super-2 number, since 2×78240361² = 12243108178820642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78240301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26356 + ... + 29173.

It is an arithmetic number, because the mean of its divisors is an integer number (19574325).

Almost surely, 2^78240361 is an apocalyptic number.

It is an amenable number.

78240361 is a deficient number, since it is larger than the sum of its proper divisors (56939).

78240361 is a wasteful number, since it uses less digits than its factorization.

78240361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56938.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 78240361 is about 8845.3581612052. The cubic root of 78240361 is about 427.7042986903.

The spelling of 78240361 in words is "seventy-eight million, two hundred forty thousand, three hundred sixty-one".