661838 has 8 divisors (see below), whose sum is σ = 1027080. Its totient is φ = 319480.

The previous prime is 661823. The next prime is 661849. The reversal of 661838 is 838166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5648 + ... + 5763.

It is an arithmetic number, because the mean of its divisors is an integer number (128385).

2⁶⁶¹⁸³⁸ is an apocalyptic number.

661838 is a deficient number, since it is larger than the sum of its proper divisors (365242).

661838 is a wasteful number, since it uses less digits than its factorization.

661838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11442.

The product of its digits is 6912, while the sum is 32.

The square root of 661838 is about 813.5342647977. The cubic root of 661838 is about 87.1466237606.

The spelling of 661838 in words is "six hundred sixty-one thousand, eight hundred thirty-eight".