20843661 has 8 divisors (see below), whose sum is σ = 27812704. Its totient is φ = 13885200.

The previous prime is 20843657. The next prime is 20843671. The reversal of 20843661 is 16634802.

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

It is not a de Polignac number, because 20843661 - 2² = 20843657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20843671) 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, 5886 + ... + 8736.

It is an arithmetic number, because the mean of its divisors is an integer number (3476588).

Almost surely, 2^20843661 is an apocalyptic number.

It is an amenable number.

20843661 is a deficient number, since it is larger than the sum of its proper divisors (6969043).

20843661 is a wasteful number, since it uses less digits than its factorization.

20843661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5291.

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 20843661 is about 4565.4858449019. The cubic root of 20843661 is about 275.2060648353.

The spelling of 20843661 in words is "twenty million, eight hundred forty-three thousand, six hundred sixty-one".