261394727904 has 72 divisors (see below), whose sum is σ = 743803423272. Its totient is φ = 87077402880.

The previous prime is 261394727879. The next prime is 261394727963. The reversal of 261394727904 is 409727493162.

261394727904 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 183199 + ... + 745889.

It is an arithmetic number, because the mean of its divisors is an integer number (10330603101).

Almost surely, 2^261394727904 is an apocalyptic number.

261394727904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261394727904 is an abundant number, since it is smaller than the sum of its proper divisors (482408695368).

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

261394727904 is a wasteful number, since it uses less digits than its factorization.

261394727904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564320 (or 564309 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 54.

The spelling of 261394727904 in words is "two hundred sixty-one billion, three hundred ninety-four million, seven hundred twenty-seven thousand, nine hundred four".