261441016649 has 4 divisors (see below), whose sum is σ = 267521040336. Its totient is φ = 255360992964.

The previous prime is 261441016631. The next prime is 261441016691. The reversal of 261441016649 is 946610144162.

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 261441016649 - 2⁸ = 261441016393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261441916649) 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, 3040011779 + ... + 3040011864.

It is an arithmetic number, because the mean of its divisors is an integer number (66880260084).

Almost surely, 2^261441016649 is an apocalyptic number.

It is an amenable number.

261441016649 is a deficient number, since it is larger than the sum of its proper divisors (6080023687).

261441016649 is an equidigital number, since it uses as much as digits as its factorization.

261441016649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6080023686.

The product of its (nonzero) digits is 248832, while the sum is 44.

The spelling of 261441016649 in words is "two hundred sixty-one billion, four hundred forty-one million, sixteen thousand, six hundred forty-nine".