261421654235455 has 16 divisors (see below), whose sum is σ = 377390658746880. Its totient is φ = 169825796435232.

The previous prime is 261421654235407. The next prime is 261421654235473. The reversal of 261421654235455 is 554532456124162.

It is not a de Polignac number, because 261421654235455 - 2⁷ = 261421654235327 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261421654235396 and 261421654235405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196557634099 + ... + 196557635428.

It is an arithmetic number, because the mean of its divisors is an integer number (23586916171680).

Almost surely, 2^{261421654235455} is an apocalyptic number.

261421654235455 is a deficient number, since it is larger than the sum of its proper divisors (115969004511425).

261421654235455 is a wasteful number, since it uses less digits than its factorization.

261421654235455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393115269558.

The product of its digits is 34560000, while the sum is 55.

The spelling of 261421654235455 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, six hundred fifty-four million, two hundred thirty-five thousand, four hundred fifty-five".