2778746897 has 2 divisors, whose sum is σ = 2778746898. Its totient is φ = 2778746896.

The previous prime is 2778746881. The next prime is 2778746921. The reversal of 2778746897 is 7986478772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2600898001 + 177848896 = 50999^2 + 13336^2 .

It is a cyclic number.

It is not a de Polignac number, because 2778746897 - 2⁴ = 2778746881 is a prime.

It is not a weakly prime, because it can be changed into another prime (2778746837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389373448 + 1389373449.

It is an arithmetic number, because the mean of its divisors is an integer number (1389373449).

Almost surely, 2^2778746897 is an apocalyptic number.

It is an amenable number.

2778746897 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778746897 is an equidigital number, since it uses as much as digits as its factorization.

2778746897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 66382848, while the sum is 65.

The square root of 2778746897 is about 52713.8207399160. The cubic root of 2778746897 is about 1405.8845671902.

The spelling of 2778746897 in words is "two billion, seven hundred seventy-eight million, seven hundred forty-six thousand, eight hundred ninety-seven".