78443557837 has 4 divisors (see below), whose sum is σ = 79923625020. Its totient is φ = 76963490656.

The previous prime is 78443557831. The next prime is 78443557849. The reversal of 78443557837 is 73875534487.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60609023721 + 17834534116 = 246189^2 + 133546^2 .

It is a cyclic number.

It is not a de Polignac number, because 78443557837 - 2¹¹ = 78443555789 is a prime.

It is a super-2 number, since 2×78443557837² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78443557831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 740033512 + ... + 740033617.

It is an arithmetic number, because the mean of its divisors is an integer number (19980906255).

Almost surely, 2^78443557837 is an apocalyptic number.

It is an amenable number.

78443557837 is a deficient number, since it is larger than the sum of its proper divisors (1480067183).

78443557837 is a wasteful number, since it uses less digits than its factorization.

78443557837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1480067182.

The product of its digits is 79027200, while the sum is 61.

The spelling of 78443557837 in words is "seventy-eight billion, four hundred forty-three million, five hundred fifty-seven thousand, eight hundred thirty-seven".