400644643 has 8 divisors (see below), whose sum is σ = 458099712. Its totient is φ = 343244616.

The previous prime is 400644641. The next prime is 400644667. The reversal of 400644643 is 346446004.

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 400644643 - 2¹ = 400644641 is a prime.

It is a super-2 number, since 2×400644643² = 321032259929194898, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (400644641) 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, 3246 + ... + 28492.

It is an arithmetic number, because the mean of its divisors is an integer number (57262464).

Almost surely, 2^400644643 is an apocalyptic number.

400644643 is a deficient number, since it is larger than the sum of its proper divisors (57455069).

400644643 is a wasteful number, since it uses less digits than its factorization.

400644643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27521.

The product of its (nonzero) digits is 27648, while the sum is 31.

The square root of 400644643 is about 20016.1095870301. The cubic root of 400644643 is about 737.2019014721.

The spelling of 400644643 in words is "four hundred million, six hundred forty-four thousand, six hundred forty-three".