278620897 has 2 divisors, whose sum is σ = 278620898. Its totient is φ = 278620896.

The previous prime is 278620877. The next prime is 278620931. The reversal of 278620897 is 798026872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 244328161 + 34292736 = 15631^2 + 5856^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-278620897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 278620897.

It is not a weakly prime, because it can be changed into another prime (278620817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139310448 + 139310449.

It is an arithmetic number, because the mean of its divisors is an integer number (139310449).

Almost surely, 2^278620897 is an apocalyptic number.

It is an amenable number.

278620897 is a deficient number, since it is larger than the sum of its proper divisors (1).

278620897 is an equidigital number, since it uses as much as digits as its factorization.

278620897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 677376, while the sum is 49.

The square root of 278620897 is about 16691.9410794551. The cubic root of 278620897 is about 653.1374134588.

The spelling of 278620897 in words is "two hundred seventy-eight million, six hundred twenty thousand, eight hundred ninety-seven".