20981803 has 2 divisors, whose sum is σ = 20981804. Its totient is φ = 20981802.

The previous prime is 20981801. The next prime is 20981827. The reversal of 20981803 is 30818902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20981803 - 2¹ = 20981801 is a prime.

Together with 20981801, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20981801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10490901 + 10490902.

It is an arithmetic number, because the mean of its divisors is an integer number (10490902).

Almost surely, 2^20981803 is an apocalyptic number.

20981803 is a deficient number, since it is larger than the sum of its proper divisors (1).

20981803 is an equidigital number, since it uses as much as digits as its factorization.

20981803 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 20981803 is about 4580.5898091840. The cubic root of 20981803 is about 275.8127054933.

The spelling of 20981803 in words is "twenty million, nine hundred eighty-one thousand, eight hundred three".