78209402879 has 4 divisors (see below), whose sum is σ = 78209971320. Its totient is φ = 78208834440.

The previous prime is 78209402863. The next prime is 78209402941. The reversal of 78209402879 is 97820490287.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 78209402879 - 2⁴ = 78209402863 is a prime.

It is a super-2 number, since 2×78209402879² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78209402849) 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, 66044 + ... + 400974.

It is an arithmetic number, because the mean of its divisors is an integer number (19552492830).

Almost surely, 2^78209402879 is an apocalyptic number.

78209402879 is a deficient number, since it is larger than the sum of its proper divisors (568441).

78209402879 is a wasteful number, since it uses less digits than its factorization.

78209402879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568440.

The product of its (nonzero) digits is 4064256, while the sum is 56.

The spelling of 78209402879 in words is "seventy-eight billion, two hundred nine million, four hundred two thousand, eight hundred seventy-nine".