78717977738 has 8 divisors (see below), whose sum is σ = 119160241860. Its totient is φ = 38997897120.

The previous prime is 78717977731. The next prime is 78717977753. The reversal of 78717977738 is 83777971787.

It can be written as a sum of positive squares in 2 ways, for example, as 78709985809 + 7991929 = 280553^2 + 2827^2 .

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

It is a super-3 number, since 3×78717977738³ (a number of 34 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78717977731) 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, 180545603 + ... + 180546038.

Almost surely, 2^78717977738 is an apocalyptic number.

78717977738 is a deficient number, since it is larger than the sum of its proper divisors (40442264122).

78717977738 is a wasteful number, since it uses less digits than its factorization.

78717977738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361091752.

The product of its digits is 203297472, while the sum is 71.

The spelling of 78717977738 in words is "seventy-eight billion, seven hundred seventeen million, nine hundred seventy-seven thousand, seven hundred thirty-eight".