646741 has 4 divisors (see below), whose sum is σ = 680800. Its totient is φ = 612684.

The previous prime is 646721. The next prime is 646757. The reversal of 646741 is 147646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 147646 = 2 ⋅73823.

It is a cyclic number.

It is not a de Polignac number, because 646741 - 2¹⁹ = 122453 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17001 + ... + 17038.

It is an arithmetic number, because the mean of its divisors is an integer number (170200).

2⁶⁴⁶⁷⁴¹ is an apocalyptic number.

It is an amenable number.

646741 is a deficient number, since it is larger than the sum of its proper divisors (34059).

646741 is a wasteful number, since it uses less digits than its factorization.

646741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34058.

The product of its digits is 4032, while the sum is 28.

The square root of 646741 is about 804.2020890299. The cubic root of 646741 is about 86.4788949145.

The spelling of 646741 in words is "six hundred forty-six thousand, seven hundred forty-one".