261245104661541 has 32 divisors (see below), whose sum is σ = 467683544014848. Its totient is φ = 125272377858240.

The previous prime is 261245104661503. The next prime is 261245104661543. The reversal of 261245104661541 is 145166401542162.

It is not a de Polignac number, because 261245104661541 - 2⁶ = 261245104661477 is a prime.

It is a super-2 number, since 2×261245104661541² (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 (261245104661543) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43497350421 + ... + 43497356426.

It is an arithmetic number, because the mean of its divisors is an integer number (14615110750464).

Almost surely, 2^{261245104661541} is an apocalyptic number.

261245104661541 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

261245104661541 is a deficient number, since it is larger than the sum of its proper divisors (206438439353307).

261245104661541 is a wasteful number, since it uses less digits than its factorization.

261245104661541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86994706881.

The product of its (nonzero) digits is 1382400, while the sum is 48.

The spelling of 261245104661541 in words is "two hundred sixty-one trillion, two hundred forty-five billion, one hundred four million, six hundred sixty-one thousand, five hundred forty-one".