261499743648001 has 2 divisors, whose sum is σ = 261499743648002. Its totient is φ = 261499743648000.

The previous prime is 261499743647983. The next prime is 261499743648029. The reversal of 261499743648001 is 100846347994162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 246966882432400 + 14532861215601 = 15715180^2 + 3812199^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261499743648001 is a prime.

It is a super-4 number, since 4×261499743648001⁴ (a number of 59 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (261499743648901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130749871824000 + 130749871824001.

It is an arithmetic number, because the mean of its divisors is an integer number (130749871824001).

Almost surely, 2^{261499743648001} is an apocalyptic number.

It is an amenable number.

261499743648001 is a deficient number, since it is larger than the sum of its proper divisors (1).

261499743648001 is an equidigital number, since it uses as much as digits as its factorization.

261499743648001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62705664, while the sum is 64.

The spelling of 261499743648001 in words is "two hundred sixty-one trillion, four hundred ninety-nine billion, seven hundred forty-three million, six hundred forty-eight thousand, one".