78491420391 has 8 divisors (see below), whose sum is σ = 110163397120. Its totient is φ = 49573528632.

The previous prime is 78491420389. The next prime is 78491420459. The reversal of 78491420391 is 19302419487.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78491420391 - 2¹ = 78491420389 is a prime.

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 78491420391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78491420311) 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 7 ways as a sum of consecutive naturals, for example, 688521175 + ... + 688521288.

It is an arithmetic number, because the mean of its divisors is an integer number (13770424640).

Almost surely, 2^78491420391 is an apocalyptic number.

78491420391 is a deficient number, since it is larger than the sum of its proper divisors (31671976729).

78491420391 is a wasteful number, since it uses less digits than its factorization.

78491420391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1377042485.

The product of its (nonzero) digits is 435456, while the sum is 48.

The spelling of 78491420391 in words is "seventy-eight billion, four hundred ninety-one million, four hundred twenty thousand, three hundred ninety-one".