278748397 has 2 divisors, whose sum is σ = 278748398. Its totient is φ = 278748396.

The previous prime is 278748307. The next prime is 278748427. The reversal of 278748397 is 793847872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 265396681 + 13351716 = 16291^2 + 3654^2 .

It is a cyclic number.

It is not a de Polignac number, because 278748397 - 2¹⁹ = 278224109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278748307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139374198 + 139374199.

It is an arithmetic number, because the mean of its divisors is an integer number (139374199).

Almost surely, 2^278748397 is an apocalyptic number.

It is an amenable number.

278748397 is a deficient number, since it is larger than the sum of its proper divisors (1).

278748397 is an equidigital number, since it uses as much as digits as its factorization.

278748397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4741632, while the sum is 55.

The square root of 278748397 is about 16695.7598509322. The cubic root of 278748397 is about 653.2370258973.

The spelling of 278748397 in words is "two hundred seventy-eight million, seven hundred forty-eight thousand, three hundred ninety-seven".