78696621251 has 4 divisors (see below), whose sum is σ = 79167858672. Its totient is φ = 78225383832.

The previous prime is 78696621203. The next prime is 78696621257. The reversal of 78696621251 is 15212669687.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15212669687 = 1231 ⋅12357977.

It is a cyclic number.

It is not a de Polignac number, because 78696621251 - 2¹⁰ = 78696620227 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78696621193 and 78696621202.

It is not an unprimeable number, because it can be changed into a prime (78696621257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 235618460 + ... + 235618793.

It is an arithmetic number, because the mean of its divisors is an integer number (19791964668).

Almost surely, 2^78696621251 is an apocalyptic number.

78696621251 is a deficient number, since it is larger than the sum of its proper divisors (471237421).

78696621251 is a wasteful number, since it uses less digits than its factorization.

78696621251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471237420.

The product of its digits is 2177280, while the sum is 53.

The spelling of 78696621251 in words is "seventy-eight billion, six hundred ninety-six million, six hundred twenty-one thousand, two hundred fifty-one".