261916570 has 8 divisors (see below), whose sum is σ = 471449844. Its totient is φ = 104766624.

The previous prime is 261916561. The next prime is 261916573. The reversal of 261916570 is 75619162.

It can be written as a sum of positive squares in 2 ways, for example, as 261824761 + 91809 = 16181^2 + 303^2 .

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

It is not an unprimeable number, because it can be changed into a prime (261916573) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13095819 + ... + 13095838.

Almost surely, 2^261916570 is an apocalyptic number.

261916570 is a deficient number, since it is larger than the sum of its proper divisors (209533274).

261916570 is a wasteful number, since it uses less digits than its factorization.

261916570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26191664.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 261916570 is about 16183.8366897346. The cubic root of 261916570 is about 639.8148634418.

It can be divided in two parts, 26191 and 6570, that added together give a square (32761 = 181²).

The spelling of 261916570 in words is "two hundred sixty-one million, nine hundred sixteen thousand, five hundred seventy".