261440643576543 has 8 divisors (see below), whose sum is σ = 348717740515248. Its totient is φ = 174228654511104.

The previous prime is 261440643576451. The next prime is 261440643576547. The reversal of 261440643576543 is 345675346044162.

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

It is not a de Polignac number, because 261440643576543 - 2¹² = 261440643572447 is a prime.

It is a super-2 number, since 2×261440643576543² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261440643576547) 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, 16276958946 + ... + 16276975007.

It is an arithmetic number, because the mean of its divisors is an integer number (43589717564406).

Almost surely, 2^{261440643576543} is an apocalyptic number.

261440643576543 is a deficient number, since it is larger than the sum of its proper divisors (87277096938705).

261440643576543 is a wasteful number, since it uses less digits than its factorization.

261440643576543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32553936633.

The product of its (nonzero) digits is 174182400, while the sum is 60.

The spelling of 261440643576543 in words is "two hundred sixty-one trillion, four hundred forty billion, six hundred forty-three million, five hundred seventy-six thousand, five hundred forty-three".