349721 has 4 divisors (see below), whose sum is σ = 351744. Its totient is φ = 347700.

The previous prime is 349717. The next prime is 349729. The reversal of 349721 is 127943.

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: 127943 = 97 ⋅1319.

It is a cyclic number.

It is not a de Polignac number, because 349721 - 2² = 349717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 349721.

It is not an unprimeable number, because it can be changed into a prime (349729) 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, 725 + ... + 1106.

It is an arithmetic number, because the mean of its divisors is an integer number (87936).

2³⁴⁹⁷²¹ is an apocalyptic number.

It is an amenable number.

349721 is a deficient number, since it is larger than the sum of its proper divisors (2023).

349721 is a wasteful number, since it uses less digits than its factorization.

349721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2022.

The product of its digits is 1512, while the sum is 26.

The square root of 349721 is about 591.3721332630. The cubic root of 349721 is about 70.4542566633.

It can be divided in two parts, 3497 and 21, that multiplied together give a palindrome (73437).

The spelling of 349721 in words is "three hundred forty-nine thousand, seven hundred twenty-one".