261515701 has 2 divisors, whose sum is σ = 261515702. Its totient is φ = 261515700.

The previous prime is 261515699. The next prime is 261515717. The reversal of 261515701 is 107515162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214593201 + 46922500 = 14649^2 + 6850^2 .

It is a cyclic number.

It is not a de Polignac number, because 261515701 - 2¹ = 261515699 is a prime.

Together with 261515699, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 261515701.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261512701) 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, 130757850 + 130757851.

It is an arithmetic number, because the mean of its divisors is an integer number (130757851).

Almost surely, 2^261515701 is an apocalyptic number.

It is an amenable number.

261515701 is a deficient number, since it is larger than the sum of its proper divisors (1).

261515701 is an equidigital number, since it uses as much as digits as its factorization.

261515701 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2100, while the sum is 28.

The square root of 261515701 is about 16171.4470904740. The cubic root of 261515701 is about 639.4882799216.

The spelling of 261515701 in words is "two hundred sixty-one million, five hundred fifteen thousand, seven hundred one".