3126721 has 4 divisors (see below), whose sum is σ = 3367252. Its totient is φ = 2886192.

The previous prime is 3126713. The next prime is 3126727. The reversal of 3126721 is 1276213.

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 680625 + 2446096 = 825^2 + 1564^2 .

It is a cyclic number.

It is not a de Polignac number, because 3126721 - 2³ = 3126713 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3126692 and 3126701.

It is not an unprimeable number, because it can be changed into a prime (3126727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120246 + ... + 120271.

It is an arithmetic number, because the mean of its divisors is an integer number (841813).

Almost surely, 2^3126721 is an apocalyptic number.

It is an amenable number.

3126721 is a deficient number, since it is larger than the sum of its proper divisors (240531).

3126721 is a wasteful number, since it uses less digits than its factorization.

3126721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240530.

The product of its digits is 504, while the sum is 22.

The square root of 3126721 is about 1768.2536582742. The cubic root of 3126721 is about 146.2277205694.

The spelling of 3126721 in words is "three million, one hundred twenty-six thousand, seven hundred twenty-one".