261666374641419 has 64 divisors (see below), whose sum is σ = 412567702732800. Its totient is φ = 145847133801600.

The previous prime is 261666374641391. The next prime is 261666374641433. The reversal of 261666374641419 is 914146473666162.

It is not a de Polignac number, because 261666374641419 - 2¹⁹ = 261666374117131 is a prime.

It is a super-3 number, since 3×261666374641419³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (66) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 261666374641419.

It is not an unprimeable number, because it can be changed into a prime (261666374641499) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 19609627 + ... + 30130884.

It is an arithmetic number, because the mean of its divisors is an integer number (6446370355200).

Almost surely, 2^{261666374641419} is an apocalyptic number.

261666374641419 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

261666374641419 is a deficient number, since it is larger than the sum of its proper divisors (150901328091381).

261666374641419 is a wasteful number, since it uses less digits than its factorization.

261666374641419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49740816.

The product of its digits is 188116992, while the sum is 66.

The spelling of 261666374641419 in words is "two hundred sixty-one trillion, six hundred sixty-six billion, three hundred seventy-four million, six hundred forty-one thousand, four hundred nineteen".