261604481 has 2 divisors, whose sum is σ = 261604482. Its totient is φ = 261604480.

The previous prime is 261604459. The next prime is 261604513. The reversal of 261604481 is 184406162.

261604481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (261604513) can be obtained adding 261604481 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208080625 + 53523856 = 14425^2 + 7316^2 .

It is a cyclic number.

It is not a de Polignac number, because 261604481 - 2¹⁴ = 261588097 is a prime.

It is a super-2 number, since 2×261604481² = 136873808958558722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (261606481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130802240 + 130802241.

It is an arithmetic number, because the mean of its divisors is an integer number (130802241).

Almost surely, 2^261604481 is an apocalyptic number.

It is an amenable number.

261604481 is a deficient number, since it is larger than the sum of its proper divisors (1).

261604481 is an equidigital number, since it uses as much as digits as its factorization.

261604481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 261604481 is about 16174.1918190678. The cubic root of 261604481 is about 639.5606367577.

The spelling of 261604481 in words is "two hundred sixty-one million, six hundred four thousand, four hundred eighty-one".