2780216999 has 4 divisors (see below), whose sum is σ = 3177390864. Its totient is φ = 2383043136.

The previous prime is 2780216993. The next prime is 2780217019. The reversal of 2780216999 is 9996120872.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2780216999 - 2¹⁶ = 2780151463 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2780216999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2780216993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198586922 + ... + 198586935.

It is an arithmetic number, because the mean of its divisors is an integer number (794347716).

Almost surely, 2^2780216999 is an apocalyptic number.

2780216999 is a deficient number, since it is larger than the sum of its proper divisors (397173865).

2780216999 is an equidigital number, since it uses as much as digits as its factorization.

2780216999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397173864.

The product of its (nonzero) digits is 979776, while the sum is 53.

The square root of 2780216999 is about 52727.7630760115. The cubic root of 2780216999 is about 1406.1324522282.

The spelling of 2780216999 in words is "two billion, seven hundred eighty million, two hundred sixteen thousand, nine hundred ninety-nine".