20301821 has 2 divisors, whose sum is σ = 20301822. Its totient is φ = 20301820.

The previous prime is 20301817. The next prime is 20301829. The reversal of 20301821 is 12810302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17757796 + 2544025 = 4214^2 + 1595^2 .

It is a cyclic number.

It is not a de Polignac number, because 20301821 - 2² = 20301817 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20301821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20301829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10150910 + 10150911.

It is an arithmetic number, because the mean of its divisors is an integer number (10150911).

Almost surely, 2^20301821 is an apocalyptic number.

It is an amenable number.

20301821 is a deficient number, since it is larger than the sum of its proper divisors (1).

20301821 is an equidigital number, since it uses as much as digits as its factorization.

20301821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 20301821 is about 4505.7542098965. The cubic root of 20301821 is about 272.8003970620.

The spelling of 20301821 in words is "twenty million, three hundred one thousand, eight hundred twenty-one".