2240721 has 18 divisors (see below), whose sum is σ = 3765762. Its totient is φ = 1280160.

The previous prime is 2240701. The next prime is 2240723. The reversal of 2240721 is 1270422.

It can be written as a sum of positive squares in only one way, i.e., 1535121 + 705600 = 1239^2 + 840^2 .

It is not a de Polignac number, because 2240721 - 2⁶ = 2240657 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2240694 and 2240703.

It is not an unprimeable number, because it can be changed into a prime (2240723) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2100 + ... + 2981.

It is an arithmetic number, because the mean of its divisors is an integer number (209209).

2^2240721 is an apocalyptic number.

2240721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2240721 is a deficient number, since it is larger than the sum of its proper divisors (1525041).

2240721 is a wasteful number, since it uses less digits than its factorization.

2240721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5101 (or 5091 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 2240721 is about 1496.9038045245. The cubic root of 2240721 is about 130.8566892279.

Subtracting from 2240721 its reverse (1270422), we obtain a cube (970299 = 99³).

The spelling of 2240721 in words is "two million, two hundred forty thousand, seven hundred twenty-one".