261913481 has 2 divisors, whose sum is σ = 261913482. Its totient is φ = 261913480.

The previous prime is 261913459. The next prime is 261913493. The reversal of 261913481 is 184319162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 224520256 + 37393225 = 14984^2 + 6115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261913481 is a prime.

It is a super-2 number, since 2×261913481² = 137197343059074722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (261013481) 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, 130956740 + 130956741.

It is an arithmetic number, because the mean of its divisors is an integer number (130956741).

Almost surely, 2^261913481 is an apocalyptic number.

It is an amenable number.

261913481 is a deficient number, since it is larger than the sum of its proper divisors (1).

261913481 is an equidigital number, since it uses as much as digits as its factorization.

261913481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 35.

The square root of 261913481 is about 16183.7412547285. The cubic root of 261913481 is about 639.8123481423.

The spelling of 261913481 in words is "two hundred sixty-one million, nine hundred thirteen thousand, four hundred eighty-one".