261543102054426 has 24 divisors (see below), whose sum is σ = 568156294817280. Its totient is φ = 86953407295176.

The previous prime is 261543102054383. The next prime is 261543102054473. The reversal of 261543102054426 is 624450201345162.

It is a happy number.

261543102054426 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 4 + 3 + 10 + 205 + 4 + 426 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18968886496 + ... + 18968900283.

It is an arithmetic number, because the mean of its divisors is an integer number (23673178950720).

Almost surely, 2^{261543102054426} is an apocalyptic number.

261543102054426 is an abundant number, since it is smaller than the sum of its proper divisors (306613192762854).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261543102054426 is a wasteful number, since it uses less digits than its factorization.

261543102054426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37937787170 (or 37937787167 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 45.

Adding to 261543102054426 its reverse (624450201345162), we get a palindrome (885993303399588).

The spelling of 261543102054426 in words is "two hundred sixty-one trillion, five hundred forty-three billion, one hundred two million, fifty-four thousand, four hundred twenty-six".