78375609 has 27 divisors (see below), whose sum is σ = 123129903. Its totient is φ = 48018672.

The previous prime is 78375601. The next prime is 78375611. The reversal of 78375609 is 90657387.

It is a happy number.

The square root of 78375609 is 8853.

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

78375609 is a `hidden beast` number, since 7 + 8 + 37 + 5 + 609 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11594025 + 66781584 = 3405^2 + 8172^2 .

It is not a de Polignac number, because 78375609 - 2³ = 78375601 is a prime.

It is a super-2 number, since 2×78375609² = 12285472172241762, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78375601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 345154 + ... + 345380.

Almost surely, 2^78375609 is an apocalyptic number.

78375609 is the 8853-rd square number.

78375609 is the 4427-th centered octagonal number.

It is an amenable number.

78375609 is a deficient number, since it is larger than the sum of its proper divisors (44754294).

78375609 is a wasteful number, since it uses less digits than its factorization.

78375609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 317520, while the sum is 45.

The cubic root of 78375609 is about 427.9506031588.

The spelling of 78375609 in words is "seventy-eight million, three hundred seventy-five thousand, six hundred nine".