261888001 has 4 divisors (see below), whose sum is σ = 275671600. Its totient is φ = 248104404.

The previous prime is 261887993. The next prime is 261888007. The reversal of 261888001 is 100888162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261888001 - 2³ = 261887993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261888007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6891771 + ... + 6891808.

It is an arithmetic number, because the mean of its divisors is an integer number (68917900).

Almost surely, 2^261888001 is an apocalyptic number.

It is an amenable number.

261888001 is a deficient number, since it is larger than the sum of its proper divisors (13783599).

261888001 is a wasteful number, since it uses less digits than its factorization.

261888001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13783598.

The product of its (nonzero) digits is 6144, while the sum is 34.

The square root of 261888001 is about 16182.9540257643. The cubic root of 261888001 is about 639.7915996273.

The spelling of 261888001 in words is "two hundred sixty-one million, eight hundred eighty-eight thousand, one".