401669 has 2 divisors, whose sum is σ = 401670. Its totient is φ = 401668.

The previous prime is 401651. The next prime is 401671. The reversal of 401669 is 966104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 289444 + 112225 = 538^2 + 335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-401669 is a prime.

It is a super-2 number, since 2×401669² = 322675971122, which contains 22 as substring.

Together with 401671, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200834 + 200835.

It is an arithmetic number, because the mean of its divisors is an integer number (200835).

2⁴⁰¹⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

401669 is a deficient number, since it is larger than the sum of its proper divisors (1).

401669 is an equidigital number, since it uses as much as digits as its factorization.

401669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 401669 is about 633.7736188893. The cubic root of 401669 is about 73.7829652494.

The spelling of 401669 in words is "four hundred one thousand, six hundred sixty-nine".