20898949 has 2 divisors, whose sum is σ = 20898950. Its totient is φ = 20898948.

The previous prime is 20898931. The next prime is 20898953. The reversal of 20898949 is 94989802.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20638849 + 260100 = 4543^2 + 510^2 .

It is a cyclic number.

It is not a de Polignac number, because 20898949 - 2¹¹ = 20896901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20898149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10449474 + 10449475.

It is an arithmetic number, because the mean of its divisors is an integer number (10449475).

Almost surely, 2^20898949 is an apocalyptic number.

It is an amenable number.

20898949 is a deficient number, since it is larger than the sum of its proper divisors (1).

20898949 is an equidigital number, since it uses as much as digits as its factorization.

20898949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 373248, while the sum is 49.

The square root of 20898949 is about 4571.5368313074. The cubic root of 20898949 is about 275.4491788694.

The spelling of 20898949 in words is "twenty million, eight hundred ninety-eight thousand, nine hundred forty-nine".