78778912749 has 12 divisors (see below), whose sum is σ = 105342610464. Its totient is φ = 52367682664.

The previous prime is 78778912727. The next prime is 78778912753. The reversal of 78778912749 is 94721987787.

It is not a de Polignac number, because 78778912749 - 2¹⁹ = 78778388461 is a prime.

It is a super-2 number, since 2×78778912749² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78778912249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 252184 + ... + 470270.

It is an arithmetic number, because the mean of its divisors is an integer number (8778550872).

Almost surely, 2^78778912749 is an apocalyptic number.

It is an amenable number.

78778912749 is a deficient number, since it is larger than the sum of its proper divisors (26563697715).

78778912749 is an equidigital number, since it uses as much as digits as its factorization.

78778912749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218784 (or 218437 counting only the distinct ones).

The product of its digits is 99574272, while the sum is 69.

The spelling of 78778912749 in words is "seventy-eight billion, seven hundred seventy-eight million, nine hundred twelve thousand, seven hundred forty-nine".