20754785509 has 2 divisors, whose sum is σ = 20754785510. Its totient is φ = 20754785508.

The previous prime is 20754785503. The next prime is 20754785567. The reversal of 20754785509 is 90558745702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12824883009 + 7929902500 = 113247^2 + 89050^2 .

It is a cyclic number.

It is not a de Polignac number, because 20754785509 - 2¹³ = 20754777317 is a prime.

It is a super-2 number, since 2×20754785509² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20754785503) 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, 10377392754 + 10377392755.

It is an arithmetic number, because the mean of its divisors is an integer number (10377392755).

Almost surely, 2^20754785509 is an apocalyptic number.

It is an amenable number.

20754785509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20754785509 is an equidigital number, since it uses as much as digits as its factorization.

20754785509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528000, while the sum is 52.

The spelling of 20754785509 in words is "twenty billion, seven hundred fifty-four million, seven hundred eighty-five thousand, five hundred nine".