261543745573633 has 8 divisors (see below), whose sum is σ = 265831642906920. Its totient is φ = 257255857754880.

The previous prime is 261543745573609. The next prime is 261543745573697. The reversal of 261543745573633 is 336375547345162.

261543745573633 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8803160208144 + 252740585365489 = 2967012^2 + 15897817^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261543745573633 - 2³³ = 261535155639041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261543745573603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71917641 + ... + 75466777.

It is an arithmetic number, because the mean of its divisors is an integer number (33228955363365).

Almost surely, 2^{261543745573633} is an apocalyptic number.

It is an amenable number.

261543745573633 is a deficient number, since it is larger than the sum of its proper divisors (4287897333287).

261543745573633 is a wasteful number, since it uses less digits than its factorization.

261543745573633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4757267.

The product of its digits is 571536000, while the sum is 64.

The spelling of 261543745573633 in words is "two hundred sixty-one trillion, five hundred forty-three billion, seven hundred forty-five million, five hundred seventy-three thousand, six hundred thirty-three".