261868001 has 4 divisors (see below), whose sum is σ = 262992132. Its totient is φ = 260743872.

The previous prime is 261867989. The next prime is 261868027. The reversal of 261868001 is 100868162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 100868162 = 2 ⋅50434081.

It can be written as a sum of positive squares in 2 ways, for example, as 24245776 + 237622225 = 4924^2 + 15415^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261868001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261868081) 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, 561716 + ... + 562181.

It is an arithmetic number, because the mean of its divisors is an integer number (65748033).

Almost surely, 2^261868001 is an apocalyptic number.

It is an amenable number.

261868001 is a deficient number, since it is larger than the sum of its proper divisors (1124131).

261868001 is a wasteful number, since it uses less digits than its factorization.

261868001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124130.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 261868001 is about 16182.3360798125. The cubic root of 261868001 is about 639.7753125661.

The spelling of 261868001 in words is "two hundred sixty-one million, eight hundred sixty-eight thousand, one".