2780397 has 6 divisors (see below), whose sum is σ = 4016142. Its totient is φ = 1853592.

The previous prime is 2780369. The next prime is 2780399. The reversal of 2780397 is 7930872.

It can be written as a sum of positive squares in only one way, i.e., 1758276 + 1022121 = 1326^2 + 1011^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2780397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2780399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 154458 + ... + 154475.

It is an arithmetic number, because the mean of its divisors is an integer number (669357).

2^2780397 is an apocalyptic number.

It is an amenable number.

2780397 is a deficient number, since it is larger than the sum of its proper divisors (1235745).

2780397 is a wasteful number, since it uses less digits than its factorization.

2780397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308939 (or 308936 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 2780397 is about 1667.4522481918. The cubic root of 2780397 is about 140.6162797556.

The spelling of 2780397 in words is "two million, seven hundred eighty thousand, three hundred ninety-seven".