78821625161 has 4 divisors (see below), whose sum is σ = 78852623232. Its totient is φ = 78790627092.

The previous prime is 78821625149. The next prime is 78821625167. The reversal of 78821625161 is 16152612887.

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 78821625161 - 2³⁴ = 61641755977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78821625167) 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, 15495221 + ... + 15500306.

It is an arithmetic number, because the mean of its divisors is an integer number (19713155808).

Almost surely, 2^78821625161 is an apocalyptic number.

It is an amenable number.

78821625161 is a deficient number, since it is larger than the sum of its proper divisors (30998071).

78821625161 is a wasteful number, since it uses less digits than its factorization.

78821625161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30998070.

The product of its digits is 322560, while the sum is 47.

The spelling of 78821625161 in words is "seventy-eight billion, eight hundred twenty-one million, six hundred twenty-five thousand, one hundred sixty-one".