261017066 has 4 divisors (see below), whose sum is σ = 391525602. Its totient is φ = 130508532.

The previous prime is 261017063. The next prime is 261017069. The reversal of 261017066 is 660710162.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (261017063) and next prime (261017069).

It can be written as a sum of positive squares in only one way, i.e., 215062225 + 45954841 = 14665^2 + 6779^2 .

It is not an unprimeable number, because it can be changed into a prime (261017063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65254265 + ... + 65254268.

Almost surely, 2^261017066 is an apocalyptic number.

261017066 is a deficient number, since it is larger than the sum of its proper divisors (130508536).

261017066 is a wasteful number, since it uses less digits than its factorization.

261017066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130508535.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 261017066 is about 16156.0225922100. The cubic root of 261017066 is about 639.0815814362.

The spelling of 261017066 in words is "two hundred sixty-one million, seventeen thousand, sixty-six".