20988101 has 2 divisors, whose sum is σ = 20988102. Its totient is φ = 20988100.

The previous prime is 20988089. The next prime is 20988109. The reversal of 20988101 is 10188902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13315201 + 7672900 = 3649^2 + 2770^2 .

It is a cyclic number.

It is not a de Polignac number, because 20988101 - 2²² = 16793797 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_1329248 and since 20988101 and 1329248 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20988109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10494050 + 10494051.

It is an arithmetic number, because the mean of its divisors is an integer number (10494051).

Almost surely, 2^20988101 is an apocalyptic number.

It is an amenable number.

20988101 is a deficient number, since it is larger than the sum of its proper divisors (1).

20988101 is an equidigital number, since it uses as much as digits as its factorization.

20988101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 20988101 is about 4581.2772236572. The cubic root of 20988101 is about 275.8402991601.

The spelling of 20988101 in words is "twenty million, nine hundred eighty-eight thousand, one hundred one".