401721 has 8 divisors (see below), whose sum is σ = 538560. Its totient is φ = 266352.

The previous prime is 401711. The next prime is 401743. The reversal of 401721 is 127104.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 401721 - 2⁵ = 401689 is a prime.

It is a super-2 number, since 2×401721² = 322759523682, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 401721.

It is not an unprimeable number, because it can be changed into a prime (401711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 891 + ... + 1263.

It is an arithmetic number, because the mean of its divisors is an integer number (67320).

2⁴⁰¹⁷²¹ is an apocalyptic number.

It is an amenable number.

401721 is a deficient number, since it is larger than the sum of its proper divisors (136839).

401721 is a wasteful number, since it uses less digits than its factorization.

401721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 401721 is about 633.8146416737. The cubic root of 401721 is about 73.7861490887.

Adding to 401721 its reverse (127104), we get a palindrome (528825).

The spelling of 401721 in words is "four hundred one thousand, seven hundred twenty-one", and thus it is an iban number.