78219217439 has 4 divisors (see below), whose sum is σ = 85330055400. Its totient is φ = 71108379480.

The previous prime is 78219217403. The next prime is 78219217477. The reversal of 78219217439 is 93471291287.

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

It is a cyclic number.

It is not a de Polignac number, because 78219217439 - 2¹⁶ = 78219151903 is a prime.

It is a super-2 number, since 2×78219217439² (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 (78219213439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3555418964 + ... + 3555418985.

It is an arithmetic number, because the mean of its divisors is an integer number (21332513850).

Almost surely, 2^78219217439 is an apocalyptic number.

78219217439 is a deficient number, since it is larger than the sum of its proper divisors (7110837961).

78219217439 is a wasteful number, since it uses less digits than its factorization.

78219217439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7110837960.

The product of its digits is 1524096, while the sum is 53.

The spelling of 78219217439 in words is "seventy-eight billion, two hundred nineteen million, two hundred seventeen thousand, four hundred thirty-nine".