78164856961 has 4 divisors (see below), whose sum is σ = 79827939072. Its totient is φ = 76501774852.

The previous prime is 78164856919. The next prime is 78164856997. The reversal of 78164856961 is 16965846187.

It is a happy number.

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: 16965846187 = 19 ⋅892939273.

It is a cyclic number.

It is not a de Polignac number, because 78164856961 - 2⁹ = 78164856449 is a prime.

It is a super-2 number, since 2×78164856961² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78164856961.

It is not an unprimeable number, because it can be changed into a prime (78164856901) 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, 831540985 + ... + 831541078.

It is an arithmetic number, because the mean of its divisors is an integer number (19956984768).

Almost surely, 2^78164856961 is an apocalyptic number.

It is an amenable number.

78164856961 is a deficient number, since it is larger than the sum of its proper divisors (1663082111).

78164856961 is a wasteful number, since it uses less digits than its factorization.

78164856961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663082110.

The product of its digits is 17418240, while the sum is 61.

The spelling of 78164856961 in words is "seventy-eight billion, one hundred sixty-four million, eight hundred fifty-six thousand, nine hundred sixty-one".