2447721 has 6 divisors (see below), whose sum is σ = 3535610. Its totient is φ = 1631808.

The previous prime is 2447717. The next prime is 2447723. The reversal of 2447721 is 1277442.

It is a happy number.

2447721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1929321 + 518400 = 1389^2 + 720^2 .

It is not a de Polignac number, because 2447721 - 2² = 2447717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2447723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 135976 + ... + 135993.

2^2447721 is an apocalyptic number.

It is an amenable number.

2447721 is a deficient number, since it is larger than the sum of its proper divisors (1087889).

2447721 is a wasteful number, since it uses less digits than its factorization.

2447721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271975 (or 271972 counting only the distinct ones).

The product of its digits is 3136, while the sum is 27.

The square root of 2447721 is about 1564.5194150281. The cubic root of 2447721 is about 134.7681617582.

The spelling of 2447721 in words is "two million, four hundred forty-seven thousand, seven hundred twenty-one".