78242367778261 has 16 divisors (see below), whose sum is σ = 81651822292800. Its totient is φ = 74882788460928.

The previous prime is 78242367778241. The next prime is 78242367778303. The reversal of 78242367778261 is 16287776324287.

It is a cyclic number.

It is not a de Polignac number, because 78242367778261 - 2¹³ = 78242367770069 is a prime.

It is a super-2 number, since 2×78242367778261² (a number of 29 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 (78242367778241) 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 15 ways as a sum of consecutive naturals, for example, 20045176 + ... + 23628241.

It is an arithmetic number, because the mean of its divisors is an integer number (5103238893300).

Almost surely, 2^{78242367778261} is an apocalyptic number.

It is an amenable number.

78242367778261 is a deficient number, since it is larger than the sum of its proper divisors (3409454514539).

78242367778261 is a wasteful number, since it uses less digits than its factorization.

78242367778261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43673988.

The product of its digits is 531062784, while the sum is 70.

The spelling of 78242367778261 in words is "seventy-eight trillion, two hundred forty-two billion, three hundred sixty-seven million, seven hundred seventy-eight thousand, two hundred sixty-one".