261017007561604 has 48 divisors (see below), whose sum is σ = 522213955175808. Its totient is φ = 111825878128128.

The previous prime is 261017007561601. The next prime is 261017007561613. The reversal of 261017007561604 is 406165700710162.

It is not an unprimeable number, because it can be changed into a prime (261017007561601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1394101404 + ... + 1394288620.

It is an arithmetic number, because the mean of its divisors is an integer number (10879457399496).

Almost surely, 2^{261017007561604} is an apocalyptic number.

It is an amenable number.

261017007561604 is an abundant number, since it is smaller than the sum of its proper divisors (261196947614204).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261017007561604 is a wasteful number, since it uses less digits than its factorization.

261017007561604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204124 (or 204122 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 46.

The spelling of 261017007561604 in words is "two hundred sixty-one trillion, seventeen billion, seven million, five hundred sixty-one thousand, six hundred four".