261641201 has 4 divisors (see below), whose sum is σ = 262048752. Its totient is φ = 261233652.

The previous prime is 261641179. The next prime is 261641249. The reversal of 261641201 is 102146162.

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, and also an emirpimes, since its reverse is a distinct semiprime: 102146162 = 2 ⋅51073081.

It is a cyclic number.

It is not a de Polignac number, because 261641201 - 2⁶ = 261641137 is a prime.

It is a super-2 number, since 2×261641201² = 136912236121444802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261641291) 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, 202811 + ... + 204096.

It is an arithmetic number, because the mean of its divisors is an integer number (65512188).

Almost surely, 2^261641201 is an apocalyptic number.

It is an amenable number.

261641201 is a deficient number, since it is larger than the sum of its proper divisors (407551).

261641201 is an equidigital number, since it uses as much as digits as its factorization.

261641201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407550.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 261641201 is about 16175.3269209621. The cubic root of 261641201 is about 639.5905592420.

Adding to 261641201 its reverse (102146162), we get a palindrome (363787363).

The spelling of 261641201 in words is "two hundred sixty-one million, six hundred forty-one thousand, two hundred one".