2397721 has 4 divisors (see below), whose sum is σ = 2456244. Its totient is φ = 2339200.

The previous prime is 2397719. The next prime is 2397793. The reversal of 2397721 is 1277932.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1265625 + 1132096 = 1125^2 + 1064^2 .

It is a cyclic number.

It is not a de Polignac number, because 2397721 - 2¹ = 2397719 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2397821) 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, 29200 + ... + 29281.

It is an arithmetic number, because the mean of its divisors is an integer number (614061).

2^2397721 is an apocalyptic number.

It is an amenable number.

2397721 is a deficient number, since it is larger than the sum of its proper divisors (58523).

2397721 is an equidigital number, since it uses as much as digits as its factorization.

2397721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58522.

The product of its digits is 5292, while the sum is 31.

The square root of 2397721 is about 1548.4576196977. The cubic root of 2397721 is about 133.8441977705.

The spelling of 2397721 in words is "two million, three hundred ninety-seven thousand, seven hundred twenty-one".