261543700315021 has 8 divisors (see below), whose sum is σ = 261791881284024. Its totient is φ = 261295537132800.

The previous prime is 261543700314991. The next prime is 261543700315043. The reversal of 261543700315021 is 120513007345162.

It can be written as a sum of positive squares in 4 ways, for example, as 48996780052900 + 212546920262121 = 6999770^2 + 14578989^2 .

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 261543700315021 - 2¹⁷ = 261543700183949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261543700315421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25068921 + ... + 33934321.

It is an arithmetic number, because the mean of its divisors is an integer number (32723985160503).

Almost surely, 2^{261543700315021} is an apocalyptic number.

It is an amenable number.

261543700315021 is a deficient number, since it is larger than the sum of its proper divisors (248180969003).

261543700315021 is a wasteful number, since it uses less digits than its factorization.

261543700315021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8893391.

The product of its (nonzero) digits is 151200, while the sum is 40.

The spelling of 261543700315021 in words is "two hundred sixty-one trillion, five hundred forty-three billion, seven hundred million, three hundred fifteen thousand, twenty-one".