78364381421 has 8 divisors (see below), whose sum is σ = 82177105080. Its totient is φ = 74625691392.

The previous prime is 78364381393. The next prime is 78364381423. The reversal of 78364381421 is 12418346387.

It can be written as a sum of positive squares in 4 ways, for example, as 24480044521 + 53884336900 = 156461^2 + 232130^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 78364381421 - 2¹⁰ = 78364380397 is a prime.

It is a super-2 number, since 2×78364381421² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78364381423) 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 7 ways as a sum of consecutive naturals, for example, 18506240 + ... + 18510473.

It is an arithmetic number, because the mean of its divisors is an integer number (10272138135).

Almost surely, 2^78364381421 is an apocalyptic number.

It is an amenable number.

78364381421 is a deficient number, since it is larger than the sum of its proper divisors (3812723659).

78364381421 is a wasteful number, since it uses less digits than its factorization.

78364381421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37016815.

The product of its digits is 774144, while the sum is 47.

The spelling of 78364381421 in words is "seventy-eight billion, three hundred sixty-four million, three hundred eighty-one thousand, four hundred twenty-one".