78199949281 has 2 divisors, whose sum is σ = 78199949282. Its totient is φ = 78199949280.

The previous prime is 78199949263. The next prime is 78199949287. The reversal of 78199949281 is 18294999187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74428024225 + 3771925056 = 272815^2 + 61416^2 .

It is a cyclic number.

It is not a de Polignac number, because 78199949281 - 2¹³ = 78199941089 is a prime.

It is a super-2 number, since 2×78199949281² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78199949287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39099974640 + 39099974641.

It is an arithmetic number, because the mean of its divisors is an integer number (39099974641).

Almost surely, 2^78199949281 is an apocalyptic number.

It is an amenable number.

78199949281 is a deficient number, since it is larger than the sum of its proper divisors (1).

78199949281 is an equidigital number, since it uses as much as digits as its factorization.

78199949281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23514624, while the sum is 67.

The spelling of 78199949281 in words is "seventy-eight billion, one hundred ninety-nine million, nine hundred forty-nine thousand, two hundred eighty-one".