261442165415541 has 96 divisors (see below), whose sum is σ = 416410093424640. Its totient is φ = 145242665568000.

The previous prime is 261442165415513. The next prime is 261442165415551. The reversal of 261442165415541 is 145514561244162.

It is not a de Polignac number, because 261442165415541 - 2¹⁰ = 261442165414517 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261442165415551) 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 95 ways as a sum of consecutive naturals, for example, 1257295006 + ... + 1257502928.

It is an arithmetic number, because the mean of its divisors is an integer number (4337605139840).

Almost surely, 2^{261442165415541} is an apocalyptic number.

It is an amenable number.

261442165415541 is a deficient number, since it is larger than the sum of its proper divisors (154967928009099).

261442165415541 is a wasteful number, since it uses less digits than its factorization.

261442165415541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213879 (or 213868 counting only the distinct ones).

The product of its digits is 4608000, while the sum is 51.

The spelling of 261442165415541 in words is "two hundred sixty-one trillion, four hundred forty-two billion, one hundred sixty-five million, four hundred fifteen thousand, five hundred forty-one".