20988437 has 2 divisors, whose sum is σ = 20988438. Its totient is φ = 20988436.

The previous prime is 20988403. The next prime is 20988467. The reversal of 20988437 is 73488902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17859076 + 3129361 = 4226^2 + 1769^2 .

It is a cyclic number.

It is not a de Polignac number, because 20988437 - 2¹⁰ = 20987413 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20988394 and 20988403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20988467) 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, 10494218 + 10494219.

It is an arithmetic number, because the mean of its divisors is an integer number (10494219).

Almost surely, 2^20988437 is an apocalyptic number.

It is an amenable number.

20988437 is a deficient number, since it is larger than the sum of its proper divisors (1).

20988437 is an equidigital number, since it uses as much as digits as its factorization.

20988437 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 20988437 is about 4581.3138945067. The cubic root of 20988437 is about 275.8417711346.

The spelling of 20988437 in words is "twenty million, nine hundred eighty-eight thousand, four hundred thirty-seven".