347721 has 16 divisors (see below), whose sum is σ = 520128. Its totient is φ = 204800.

The previous prime is 347717. The next prime is 347729. The reversal of 347721 is 127743.

347721 = T₄₈ + T₄₉ + ... + T₁₂₉.

It is a 5-Lehmer number, since φ(347721) divides (347721-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 347721 - 2² = 347717 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 347691 and 347700.

It is not an unprimeable number, because it can be changed into a prime (347729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1225 + ... + 1481.

It is an arithmetic number, because the mean of its divisors is an integer number (32508).

2³⁴⁷⁷²¹ is an apocalyptic number.

It is an amenable number.

347721 is a deficient number, since it is larger than the sum of its proper divisors (172407).

347721 is a wasteful number, since it uses less digits than its factorization.

347721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312.

The product of its digits is 1176, while the sum is 24.

The square root of 347721 is about 589.6787260874. The cubic root of 347721 is about 70.3196941775.

The spelling of 347721 in words is "three hundred forty-seven thousand, seven hundred twenty-one", and thus it is an iban number.