2245721 has 2 divisors, whose sum is σ = 2245722. Its totient is φ = 2245720.

The previous prime is 2245687. The next prime is 2245723. The reversal of 2245721 is 1275422.

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., 1597696 + 648025 = 1264^2 + 805^2 .

It is a cyclic number.

It is not a de Polignac number, because 2245721 - 2⁶ = 2245657 is a prime.

Together with 2245723, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as 2¹⁷ + 2²⁰ + 4³ + 5⁴ + 7⁵ + 2²⁰ + 1 .

It is a plaindrome in base 16.

It is not a weakly prime, because it can be changed into another prime (2245723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1122860 + 1122861.

It is an arithmetic number, because the mean of its divisors is an integer number (1122861).

2^2245721 is an apocalyptic number.

It is an amenable number.

2245721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2245721 is an equidigital number, since it uses as much as digits as its factorization.

2245721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1120, while the sum is 23.

The square root of 2245721 is about 1498.5729878788. The cubic root of 2245721 is about 130.9539492002.

Subtracting from 2245721 its reverse (1275422), we obtain a cube (970299 = 99³).

The spelling of 2245721 in words is "two million, two hundred forty-five thousand, seven hundred twenty-one".