20015755261 has 2 divisors, whose sum is σ = 20015755262. Its totient is φ = 20015755260.

The previous prime is 20015755237. The next prime is 20015755349. The reversal of 20015755261 is 16255751002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16095743161 + 3920012100 = 126869^2 + 62610^2 .

It is a cyclic number.

It is not a de Polignac number, because 20015755261 - 2²¹ = 20013658109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20015758261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10007877630 + 10007877631.

It is an arithmetic number, because the mean of its divisors is an integer number (10007877631).

Almost surely, 2^20015755261 is an apocalyptic number.

It is an amenable number.

20015755261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20015755261 is an equidigital number, since it uses as much as digits as its factorization.

20015755261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21000, while the sum is 34.

The spelling of 20015755261 in words is "twenty billion, fifteen million, seven hundred fifty-five thousand, two hundred sixty-one".