2781642397 has 2 divisors, whose sum is σ = 2781642398. Its totient is φ = 2781642396.

The previous prime is 2781642371. The next prime is 2781642403. The reversal of 2781642397 is 7932461872.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2543588356 + 238054041 = 50434^2 + 15429^2 .

It is a cyclic number.

It is not a de Polignac number, because 2781642397 - 2²⁷ = 2647424669 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2781642397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2781642317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1390821198 + 1390821199.

It is an arithmetic number, because the mean of its divisors is an integer number (1390821199).

Almost surely, 2^2781642397 is an apocalyptic number.

It is an amenable number.

2781642397 is a deficient number, since it is larger than the sum of its proper divisors (1).

2781642397 is an equidigital number, since it uses as much as digits as its factorization.

2781642397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1016064, while the sum is 49.

The square root of 2781642397 is about 52741.2779234633. The cubic root of 2781642397 is about 1406.3727159622.

The spelling of 2781642397 in words is "two billion, seven hundred eighty-one million, six hundred forty-two thousand, three hundred ninety-seven".