261871946401 has 32 divisors (see below), whose sum is σ = 295150399488. Its totient is φ = 230752488960.

The previous prime is 261871946381. The next prime is 261871946407. The reversal of 261871946401 is 104649178162.

261871946401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 261871946401 - 2¹⁷ = 261871815329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261871946407) 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 31 ways as a sum of consecutive naturals, for example, 6687060 + ... + 6726106.

It is an arithmetic number, because the mean of its divisors is an integer number (9223449984).

Almost surely, 2^261871946401 is an apocalyptic number.

It is an amenable number.

261871946401 is a deficient number, since it is larger than the sum of its proper divisors (33278453087).

261871946401 is a wasteful number, since it uses less digits than its factorization.

261871946401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39361.

The product of its (nonzero) digits is 580608, while the sum is 49.

The spelling of 261871946401 in words is "two hundred sixty-one billion, eight hundred seventy-one million, nine hundred forty-six thousand, four hundred one".