78665137601 has 4 divisors (see below), whose sum is σ = 79060440000. Its totient is φ = 78269835204.

The previous prime is 78665137597. The next prime is 78665137609. The reversal of 78665137601 is 10673156687.

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.

It is a cyclic number.

It is not a de Polignac number, because 78665137601 - 2² = 78665137597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 78665137601.

It is not an unprimeable number, because it can be changed into a prime (78665137609) 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, 197650901 + ... + 197651298.

It is an arithmetic number, because the mean of its divisors is an integer number (19765110000).

Almost surely, 2^78665137601 is an apocalyptic number.

It is an amenable number.

78665137601 is a deficient number, since it is larger than the sum of its proper divisors (395302399).

78665137601 is a wasteful number, since it uses less digits than its factorization.

78665137601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395302398.

The product of its (nonzero) digits is 1270080, while the sum is 50.

The spelling of 78665137601 in words is "seventy-eight billion, six hundred sixty-five million, one hundred thirty-seven thousand, six hundred one".