278808737981 has 2 divisors, whose sum is σ = 278808737982. Its totient is φ = 278808737980.

The previous prime is 278808737969. The next prime is 278808737993. The reversal of 278808737981 is 189737808872.

It is a balanced prime because it is at equal distance from previous prime (278808737969) and next prime (278808737993).

It can be written as a sum of positive squares in only one way, i.e., 240418605625 + 38390132356 = 490325^2 + 195934^2 .

It is a cyclic number.

It is not a de Polignac number, because 278808737981 - 2¹⁰ = 278808736957 is a prime.

It is a super-2 number, since 2×278808737981² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278808737951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139404368990 + 139404368991.

It is an arithmetic number, because the mean of its divisors is an integer number (139404368991).

Almost surely, 2^278808737981 is an apocalyptic number.

It is an amenable number.

278808737981 is a deficient number, since it is larger than the sum of its proper divisors (1).

278808737981 is an equidigital number, since it uses as much as digits as its factorization.

278808737981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75866112, while the sum is 68.

The spelling of 278808737981 in words is "two hundred seventy-eight billion, eight hundred eight million, seven hundred thirty-seven thousand, nine hundred eighty-one".