661043 has 8 divisors (see below), whose sum is σ = 707616. Its totient is φ = 616000.

The previous prime is 661027. The next prime is 661049. The reversal of 661043 is 340166.

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 661043 - 2⁴ = 661027 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661049) 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, 593 + ... + 1293.

It is an arithmetic number, because the mean of its divisors is an integer number (88452).

2⁶⁶¹⁰⁴³ is an apocalyptic number.

661043 is a deficient number, since it is larger than the sum of its proper divisors (46573).

661043 is a wasteful number, since it uses less digits than its factorization.

661043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 661043 is about 813.0455091814. The cubic root of 661043 is about 87.1117162632. Note that the first 3 decimals are identical.

The spelling of 661043 in words is "six hundred sixty-one thousand, forty-three".