20123764261 has 2 divisors, whose sum is σ = 20123764262. Its totient is φ = 20123764260.

The previous prime is 20123764249. The next prime is 20123764267. The reversal of 20123764261 is 16246732102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19941676225 + 182088036 = 141215^2 + 13494^2 .

It is a cyclic number.

It is not a de Polignac number, because 20123764261 - 2⁹ = 20123763749 is a prime.

It is a super-2 number, since 2×20123764261² (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 (20123764267) 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, 10061882130 + 10061882131.

It is an arithmetic number, because the mean of its divisors is an integer number (10061882131).

Almost surely, 2^20123764261 is an apocalyptic number.

It is an amenable number.

20123764261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20123764261 is an equidigital number, since it uses as much as digits as its factorization.

20123764261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 34.

The spelling of 20123764261 in words is "twenty billion, one hundred twenty-three million, seven hundred sixty-four thousand, two hundred sixty-one".