78821039807 has 2 divisors, whose sum is σ = 78821039808. Its totient is φ = 78821039806.

The previous prime is 78821039789. The next prime is 78821039827. The reversal of 78821039807 is 70893012887.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78821039807 - 2³⁰ = 77747297983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78821039827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39410519903 + 39410519904.

It is an arithmetic number, because the mean of its divisors is an integer number (39410519904).

Almost surely, 2^78821039807 is an apocalyptic number.

78821039807 is a deficient number, since it is larger than the sum of its proper divisors (1).

78821039807 is an equidigital number, since it uses as much as digits as its factorization.

78821039807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1354752, while the sum is 53.

The spelling of 78821039807 in words is "seventy-eight billion, eight hundred twenty-one million, thirty-nine thousand, eight hundred seven".