20612420261 has 2 divisors, whose sum is σ = 20612420262. Its totient is φ = 20612420260.

The previous prime is 20612420141. The next prime is 20612420291. The reversal of 20612420261 is 16202421602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19489835236 + 1122585025 = 139606^2 + 33505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20612420261 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20612420261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20612420291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10306210130 + 10306210131.

It is an arithmetic number, because the mean of its divisors is an integer number (10306210131).

Almost surely, 2^20612420261 is an apocalyptic number.

It is an amenable number.

20612420261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20612420261 is an equidigital number, since it uses as much as digits as its factorization.

20612420261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 26.

Adding to 20612420261 its reverse (16202421602), we get a palindrome (36814841863).

The spelling of 20612420261 in words is "twenty billion, six hundred twelve million, four hundred twenty thousand, two hundred sixty-one".