261186001 has 4 divisors (see below), whose sum is σ = 261226404. Its totient is φ = 261145600.

The previous prime is 261185971. The next prime is 261186007. The reversal of 261186001 is 100681162.

261186001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 92160000 + 169026001 = 9600^2 + 13001^2 .

It is a 3-Lehmer number, since φ(261186001) divides (261186001-1)³.

It is a cyclic number.

It is not a de Polignac number, because 261186001 - 2¹¹ = 261183953 is a prime.

It is a deceptive number, since it divides R_261186000.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261186007) 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, 8080 + ... + 24241.

It is an arithmetic number, because the mean of its divisors is an integer number (65306601).

It is a Poulet number, since it divides 2^261186000-1.

Almost surely, 2^261186001 is an apocalyptic number.

261186001 is the 8081-st decagonal number.

It is an amenable number.

261186001 is a deficient number, since it is larger than the sum of its proper divisors (40403).

261186001 is an equidigital number, since it uses as much as digits as its factorization.

261186001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40402.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 261186001 is about 16161.2499825973. The cubic root of 261186001 is about 639.2194267823.

The spelling of 261186001 in words is "two hundred sixty-one million, one hundred eighty-six thousand, one".