2840721 has 16 divisors (see below), whose sum is σ = 4112640. Its totient is φ = 1744080.

The previous prime is 2840699. The next prime is 2840723. The reversal of 2840721 is 1270482.

It is not a de Polignac number, because 2840721 - 2⁵ = 2840689 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2840691 and 2840700.

It is not an unprimeable number, because it can be changed into a prime (2840723) 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, 6376 + ... + 6806.

It is an arithmetic number, because the mean of its divisors is an integer number (257040).

2^2840721 is an apocalyptic number.

It is an amenable number.

2840721 is a deficient number, since it is larger than the sum of its proper divisors (1271919).

2840721 is an equidigital number, since it uses as much as digits as its factorization.

2840721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473 (or 447 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 2840721 is about 1685.4438584539. The cubic root of 2840721 is about 141.6259580072.

The spelling of 2840721 in words is "two million, eight hundred forty thousand, seven hundred twenty-one".