401657 has 4 divisors (see below), whose sum is σ = 406260. Its totient is φ = 397056.

The previous prime is 401651. The next prime is 401669. The reversal of 401657 is 756104.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22201 + 379456 = 149^2 + 616^2 .

It is a cyclic number.

It is not a de Polignac number, because 401657 - 2⁶ = 401593 is a prime.

It is a super-2 number, since 2×401657² = 322656691298, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (401651) 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, 2168 + ... + 2345.

It is an arithmetic number, because the mean of its divisors is an integer number (101565).

2⁴⁰¹⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

401657 is a deficient number, since it is larger than the sum of its proper divisors (4603).

401657 is an equidigital number, since it uses as much as digits as its factorization.

401657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4602.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 401657 is about 633.7641517158. The cubic root of 401657 is about 73.7822304782.

The spelling of 401657 in words is "four hundred one thousand, six hundred fifty-seven".