278633449889 has 2 divisors, whose sum is σ = 278633449890. Its totient is φ = 278633449888.

The previous prime is 278633449873. The next prime is 278633449903. The reversal of 278633449889 is 988944336872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 277686841600 + 946608289 = 526960^2 + 30767^2 .

It is a cyclic number.

It is not a de Polignac number, because 278633449889 - 2⁴ = 278633449873 is a prime.

It is a super-2 number, since 2×278633449889² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (278633449489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139316724944 + 139316724945.

It is an arithmetic number, because the mean of its divisors is an integer number (139316724945).

Almost surely, 2^278633449889 is an apocalyptic number.

It is an amenable number.

278633449889 is a deficient number, since it is larger than the sum of its proper divisors (1).

278633449889 is an equidigital number, since it uses as much as digits as its factorization.

278633449889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 501645312, while the sum is 71.

The spelling of 278633449889 in words is "two hundred seventy-eight billion, six hundred thirty-three million, four hundred forty-nine thousand, eight hundred eighty-nine".