78285208549 has 4 divisors (see below), whose sum is σ = 78289594336. Its totient is φ = 78280822764.

The previous prime is 78285208543. The next prime is 78285208567. The reversal of 78285208549 is 94580258287.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 94580258287 = 47 ⋅2012345921.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78285208549 is a prime.

It is a super-2 number, since 2×78285208549² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78285208493 and 78285208502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78285208543) 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, 2166009 + ... + 2201854.

It is an arithmetic number, because the mean of its divisors is an integer number (19572398584).

Almost surely, 2^78285208549 is an apocalyptic number.

It is an amenable number.

78285208549 is a deficient number, since it is larger than the sum of its proper divisors (4385787).

78285208549 is a wasteful number, since it uses less digits than its factorization.

78285208549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4385786.

The product of its (nonzero) digits is 12902400, while the sum is 58.

The spelling of 78285208549 in words is "seventy-eight billion, two hundred eighty-five million, two hundred eight thousand, five hundred forty-nine".