400069 has 2 divisors, whose sum is σ = 400070. Its totient is φ = 400068.

The previous prime is 400067. The next prime is 400087. The reversal of 400069 is 960004.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 263169 + 136900 = 513^2 + 370^2 .

It is a cyclic number.

It is not a de Polignac number, because 400069 - 2¹ = 400067 is a prime.

It is a super-2 number, since 2×400069² = 320110409522, which contains 22 as substring.

Together with 400067, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200034 + 200035.

It is an arithmetic number, because the mean of its divisors is an integer number (200035).

2⁴⁰⁰⁰⁶⁹ is an apocalyptic number.

It is an amenable number.

400069 is a deficient number, since it is larger than the sum of its proper divisors (1).

400069 is an equidigital number, since it uses as much as digits as its factorization.

400069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 400069 is about 632.5100789711. The cubic root of 400069 is about 73.6848663654.

The spelling of 400069 in words is "four hundred thousand, sixty-nine".