3549721 has 4 divisors (see below), whose sum is σ = 4056832. Its totient is φ = 3042612.

The previous prime is 3549701. The next prime is 3549731. The reversal of 3549721 is 1279453.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1279453 = 7 ⋅182779.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3549721 is a prime.

It is a d-powerful number, because it can be written as 3¹³ + 5⁹ + 4⁵ + 9³ + 7 + 2⁹ + 1 .

It is a Duffinian number.

3549721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3549701) 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, 253545 + ... + 253558.

It is an arithmetic number, because the mean of its divisors is an integer number (1014208).

Almost surely, 2^3549721 is an apocalyptic number.

It is an amenable number.

3549721 is a deficient number, since it is larger than the sum of its proper divisors (507111).

3549721 is an equidigital number, since it uses as much as digits as its factorization.

3549721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507110.

The product of its digits is 7560, while the sum is 31.

The square root of 3549721 is about 1884.0703277744. The cubic root of 3549721 is about 152.5450337305.

The spelling of 3549721 in words is "three million, five hundred forty-nine thousand, seven hundred twenty-one".