2749216821 has 16 divisors (see below), whose sum is σ = 3959538240. Its totient is φ = 1686706560.

The previous prime is 2749216819. The next prime is 2749216823. The reversal of 2749216821 is 1286129472.

It is an interprime number because it is at equal distance from previous prime (2749216819) and next prime (2749216823).

It is not a de Polignac number, because 2749216821 - 2¹ = 2749216819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2749216823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93576 + ... + 119393.

It is an arithmetic number, because the mean of its divisors is an integer number (247471140).

Almost surely, 2^2749216821 is an apocalyptic number.

It is an amenable number.

2749216821 is a deficient number, since it is larger than the sum of its proper divisors (1210321419).

2749216821 is a wasteful number, since it uses less digits than its factorization.

2749216821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213316.

The product of its digits is 96768, while the sum is 42.

The square root of 2749216821 is about 52432.9745580012. The cubic root of 2749216821 is about 1400.8866527992.

The spelling of 2749216821 in words is "two billion, seven hundred forty-nine million, two hundred sixteen thousand, eight hundred twenty-one".