427721 has 16 divisors (see below), whose sum is σ = 528000. Its totient is φ = 345744.

The previous prime is 427717. The next prime is 427723. The reversal of 427721 is 127724.

427721 = T₁₁₉ + T₁₂₀ + ... + T₁₆₁.

It is not a de Polignac number, because 427721 - 2² = 427717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 427721.

It is not an unprimeable number, because it can be changed into a prime (427723) 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, 9926 + ... + 9968.

It is an arithmetic number, because the mean of its divisors is an integer number (33000).

2⁴²⁷⁷²¹ is an apocalyptic number.

It is an amenable number.

427721 is a deficient number, since it is larger than the sum of its proper divisors (100279).

427721 is an equidigital number, since it uses as much as digits as its factorization.

427721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 79 counting only the distinct ones).

The product of its digits is 784, while the sum is 23.

The square root of 427721 is about 654.0038226188. The cubic root of 427721 is about 75.3448416560.

The spelling of 427721 in words is "four hundred twenty-seven thousand, seven hundred twenty-one", and thus it is an iban number.