905643 has 12 divisors (see below), whose sum is σ = 1336608. Its totient is φ = 590640.

The previous prime is 905629. The next prime is 905647. The reversal of 905643 is 346509.

It is a happy number.

It is not a de Polignac number, because 905643 - 2¹⁰ = 904619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (905647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 648 + ... + 1493.

It is an arithmetic number, because the mean of its divisors is an integer number (111384).

2⁹⁰⁵⁶⁴³ is an apocalyptic number.

905643 is a deficient number, since it is larger than the sum of its proper divisors (430965).

905643 is a wasteful number, since it uses less digits than its factorization.

905643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2194 (or 2191 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 905643 is about 951.6527728116. The cubic root of 905643 is about 96.7503054695.

The spelling of 905643 in words is "nine hundred five thousand, six hundred forty-three".