20756129 has 2 divisors, whose sum is σ = 20756130. Its totient is φ = 20756128.

The previous prime is 20756101. The next prime is 20756137. The reversal of 20756129 is 92165702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10387729 + 10368400 = 3223^2 + 3220^2 .

It is a cyclic number.

It is not a de Polignac number, because 20756129 - 2¹² = 20752033 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20756095 and 20756104.

It is not a weakly prime, because it can be changed into another prime (20756159) 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, 10378064 + 10378065.

It is an arithmetic number, because the mean of its divisors is an integer number (10378065).

Almost surely, 2^20756129 is an apocalyptic number.

It is an amenable number.

20756129 is a deficient number, since it is larger than the sum of its proper divisors (1).

20756129 is an equidigital number, since it uses as much as digits as its factorization.

20756129 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 20756129 is about 4555.8894850512. The cubic root of 20756129 is about 274.8202858871.

The spelling of 20756129 in words is "twenty million, seven hundred fifty-six thousand, one hundred twenty-nine".