400001709 has 8 divisors (see below), whose sum is σ = 547750240. Its totient is φ = 259460496.

The previous prime is 400001663. The next prime is 400001729. The reversal of 400001709 is 907100004.

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

It is not a de Polignac number, because 400001709 - 2⁹ = 400001197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400001729) 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, 1801699 + ... + 1801920.

It is an arithmetic number, because the mean of its divisors is an integer number (68468780).

Almost surely, 2^400001709 is an apocalyptic number.

It is an amenable number.

400001709 is a deficient number, since it is larger than the sum of its proper divisors (147748531).

400001709 is a wasteful number, since it uses less digits than its factorization.

400001709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3603659.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 400001709 is about 20000.0427249544. The cubic root of 400001709 is about 736.8073490616.

The spelling of 400001709 in words is "four hundred million, one thousand, seven hundred nine".