400007645 has 8 divisors (see below), whose sum is σ = 480726456. Its totient is φ = 319527936.

The previous prime is 400007617. The next prime is 400007687. The reversal of 400007645 is 546700004.

It can be written as a sum of positive squares in 4 ways, for example, as 47844889 + 352162756 = 6917^2 + 18766^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 400007645 - 2¹⁴ = 399991261 is a prime.

It is a super-2 number, since 2×400007645² = 320012232116892050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56072 + ... + 62801.

It is an arithmetic number, because the mean of its divisors is an integer number (60090807).

Almost surely, 2^400007645 is an apocalyptic number.

It is an amenable number.

400007645 is a deficient number, since it is larger than the sum of its proper divisors (80718811).

400007645 is a wasteful number, since it uses less digits than its factorization.

400007645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119551.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 400007645 is about 20000.1911240868. The cubic root of 400007645 is about 736.8109937683.

Adding to 400007645 its reverse (546700004), we get a palindrome (946707649).

The spelling of 400007645 in words is "four hundred million, seven thousand, six hundred forty-five".