20611221529 has 2 divisors, whose sum is σ = 20611221530. Its totient is φ = 20611221528.

The previous prime is 20611221511. The next prime is 20611221577. The reversal of 20611221529 is 92512211602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13242715929 + 7368505600 = 115077^2 + 85840^2 .

It is a cyclic number.

It is not a de Polignac number, because 20611221529 - 2²¹ = 20609124377 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20611221529.

It is not a weakly prime, because it can be changed into another prime (20611221629) 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, 10305610764 + 10305610765.

It is an arithmetic number, because the mean of its divisors is an integer number (10305610765).

Almost surely, 2^20611221529 is an apocalyptic number.

It is an amenable number.

20611221529 is a deficient number, since it is larger than the sum of its proper divisors (1).

20611221529 is an equidigital number, since it uses as much as digits as its factorization.

20611221529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 31.

The spelling of 20611221529 in words is "twenty billion, six hundred eleven million, two hundred twenty-one thousand, five hundred twenty-nine".