3135721 has 4 divisors (see below), whose sum is σ = 3212244. Its totient is φ = 3059200.

The previous prime is 3135709. The next prime is 3135731. The reversal of 3135721 is 1275313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1275313 = 13 ⋅98101.

It can be written as a sum of positive squares in 2 ways, for example, as 55696 + 3080025 = 236^2 + 1755^2 .

It is a cyclic number.

It is not a de Polignac number, because 3135721 - 2⁷ = 3135593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3135692 and 3135701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3135731) 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, 38200 + ... + 38281.

It is an arithmetic number, because the mean of its divisors is an integer number (803061).

Almost surely, 2^3135721 is an apocalyptic number.

It is an amenable number.

3135721 is a deficient number, since it is larger than the sum of its proper divisors (76523).

3135721 is an equidigital number, since it uses as much as digits as its factorization.

3135721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76522.

The product of its digits is 630, while the sum is 22.

The square root of 3135721 is about 1770.7967133468. The cubic root of 3135721 is about 146.3678875141.

The spelling of 3135721 in words is "three million, one hundred thirty-five thousand, seven hundred twenty-one".