643461 has 16 divisors (see below), whose sum is σ = 1056384. Its totient is φ = 339264.

The previous prime is 643457. The next prime is 643463. The reversal of 643461 is 164346.

It is not a de Polignac number, because 643461 - 2² = 643457 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 906 + ... + 1451.

It is an arithmetic number, because the mean of its divisors is an integer number (66024).

2⁶⁴³⁴⁶¹ is an apocalyptic number.

It is an amenable number.

643461 is a deficient number, since it is larger than the sum of its proper divisors (412923).

643461 is a wasteful number, since it uses less digits than its factorization.

643461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2380.

The product of its digits is 1728, while the sum is 24.

The square root of 643461 is about 802.1602084372. The cubic root of 643461 is about 86.3324521343.

The spelling of 643461 in words is "six hundred forty-three thousand, four hundred sixty-one".