261555706 has 8 divisors (see below), whose sum is σ = 392666004. Its totient is φ = 130667040.

The previous prime is 261555683. The next prime is 261555709. The reversal of 261555706 is 607555162.

It can be written as a sum of positive squares in 2 ways, for example, as 260015625 + 1540081 = 16125^2 + 1241^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×261555706² = 136822774682316872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261555709) 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 in 3 ways as a sum of consecutive naturals, for example, 52425 + ... + 57196.

Almost surely, 2^261555706 is an apocalyptic number.

261555706 is a deficient number, since it is larger than the sum of its proper divisors (131110298).

261555706 is a wasteful number, since it uses less digits than its factorization.

261555706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110816.

The product of its (nonzero) digits is 63000, while the sum is 37.

The square root of 261555706 is about 16172.6839454680. The cubic root of 261555706 is about 639.5208865353.

The spelling of 261555706 in words is "two hundred sixty-one million, five hundred fifty-five thousand, seven hundred six".