20989841 has 8 divisors (see below), whose sum is σ = 21616680. Its totient is φ = 20366208.

The previous prime is 20989807. The next prime is 20989847. The reversal of 20989841 is 14898902.

It can be written as a sum of positive squares in 4 ways, for example, as 7447441 + 13542400 = 2729^2 + 3680^2 .

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 20989841 - 2¹⁴ = 20973457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20989847) 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, 20555 + ... + 21551.

It is an arithmetic number, because the mean of its divisors is an integer number (2702085).

Almost surely, 2^20989841 is an apocalyptic number.

It is an amenable number.

20989841 is a deficient number, since it is larger than the sum of its proper divisors (626839).

20989841 is an equidigital number, since it uses as much as digits as its factorization.

20989841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 20989841 is about 4581.4671230950. The cubic root of 20989841 is about 275.8479217150.

The spelling of 20989841 in words is "twenty million, nine hundred eighty-nine thousand, eight hundred forty-one".