261734521 has 2 divisors, whose sum is σ = 261734522. Its totient is φ = 261734520.

The previous prime is 261734489. The next prime is 261734569. The reversal of 261734521 is 125437162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256352121 + 5382400 = 16011^2 + 2320^2 .

It is a cyclic number.

It is not a de Polignac number, because 261734521 - 2⁵ = 261734489 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (261731521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130867260 + 130867261.

It is an arithmetic number, because the mean of its divisors is an integer number (130867261).

Almost surely, 2^261734521 is an apocalyptic number.

It is an amenable number.

261734521 is a deficient number, since it is larger than the sum of its proper divisors (1).

261734521 is an equidigital number, since it uses as much as digits as its factorization.

261734521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 31.

The square root of 261734521 is about 16178.2113040966. The cubic root of 261734521 is about 639.6665914774. Note that the first 3 decimals are identical.

The spelling of 261734521 in words is "two hundred sixty-one million, seven hundred thirty-four thousand, five hundred twenty-one".