400001656 has 8 divisors (see below), whose sum is σ = 750003120. Its totient is φ = 200000824.

The previous prime is 400001647. The next prime is 400001663. The reversal of 400001656 is 656100004.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25000096 + ... + 25000111.

It is an arithmetic number, because the mean of its divisors is an integer number (93750390).

Almost surely, 2^400001656 is an apocalyptic number.

It is an amenable number.

400001656 is a deficient number, since it is larger than the sum of its proper divisors (350001464).

400001656 is a wasteful number, since it uses less digits than its factorization.

400001656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50000213 (or 50000209 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 400001656 is about 20000.0413999572. The cubic root of 400001656 is about 736.8073165194.

The spelling of 400001656 in words is "four hundred million, one thousand, six hundred fifty-six".